Since some of the other topics seemed to be moving along and it was mentioned on another thread I thought we could open discussion on this race.

Tim

Thri-Kreen (Cost: 1 racial feat)
Average Height: 7’; 10’ to 11’ Long
Ability Scores: + 2 Dex, + 2Wis
Size: Medium
Speed: 8 squares
Vision: Normal
Languages: Thri-Kreen, Common
Skills Bonuses: + 2 Nature, + 2 Athletics
Insect body: Thri-Kreen usually need magical items resizing if taken from humanoid.
Trance: Rather than sleep, thri-kreen enter a meditative state known as trance. You need to spend 4 hours in this state to gain the same benefits other races gain from taking a 6-hour extended rest. While in a trance, you are fully aware of your surroundings and notice approaching enemies and other events as normal.
Thri-Kreen Weapon Proficiency: You gain proficiency with the Gythka and Chatkcha.
4-Handed: You have 4 hands to carry or manipulate stuff. You can only apply one bonus between a two-handed weapon or the shield in combat.
Venomous Saliva: You can use Venomous Saliva as an Encounter power.
Venomous Saliva: Thri-Kreen Racial Power
You bite an opponent and your venom cause paralysis.
Encounter (special)
Standard Action Melee 1
Attack: Con vs. Fortitude
Increase to + 2 at 11th level, + 4 at 21st level.
Hit: 1d4 + Con modifier damage, victim become immobilized (save ends).
Increase to 3d4+ Con at 11th level, 5d4 + Con at 21st level.
Special: Cannot use more venomous saliva than Con modifier per day.

To Enhanced the 4-Handed combat, here a racial feat:
4-Handed Combat [Thri-Kreen]
Prerequisite: Thri-Kreen, Two-Weapon Fighting and/or Shield Proficiency
Benefit: If you are Proficient with Shield, you can stack bonus of a two-handed weapon and a shield or 2 single-handed weapons and 2 shields.
If you are Proficient with Two-Weapon Fighting, you can instead choose to fight with 4 weapons, stacking the +1 bonus for secondary weapons.

4-Handed: You have 4 hands and are able to carry multiple things at the ready and therefor meat the requirement of more powers without the need to switch equipment. However, you may not gain a bonus for having two shields. If you take the feat two weapon fighting and use four weapons you gain a +2 instead of the normal +1.

4-Handed: You have 4 hands and are able to carry multiple things at the ready and therefor meat the requirement of more powers without the need to switch equipment. However, you may not gain a bonus for having two shields. If you take the feat two weapon fighting and use four weapons you gain a +2 instead of the normal +1. Twice per encounter you may use two at-will powers as a single standard action. This usage increases to 3 at 11th level and 4 at 21st.

I like the first one, but the second one push too much the balance. Maybe two shield can add +1 to AC.

Mantis Leap[Thri-Kreen]
Prerequisites: Thri-Kreen, Dex 15
Benefit: You can use Mantis Leap as an encounter power.

Mantis Leap Feat Power
With a great leap, you jump over obstacles and enemies accross the battlefield.
Encounter
Move Action Personal
Effect: Move up to your speed ignoring difficult terrain, and medium sized obstales or creatures.

Bite Attack[Thri-Kreen]
Prerequisites: Thri-Kreen
Benefit: You can use your bite as an unarmed attack.
Bite Prof. n/a, Damage 1d6, Group unarmed

Poisinous Bite[Thri-Kreen]
Prerequisites: Thri-Kreen, Bite Attack
Benefit: You gain Poisouns Bite as an encounter power.

Poisinous Bite Feat Power
Having the prey within your jaws, you inject a paralyzing poison in its veins.
Encounter Bite
Minor Action Meele Bite
Target One creature
Attack: Constitution vs. Fortitude
Hit: The target is stunned. Save ends.
Special: You must succesfully hit with your bite attack to use this power.

I like the idea behind redwulfe’s second “4-Handed” ability better, but yes I definitely think it’s unbalancing. This is what I’ve managed to come up with since my post in the other topic yesterday. I’m not sure exactly how to word it yet, but I figure I’d want your opinions on this first anyway.
“A Thri-Kreen can use two of his limbs to wield a versatile weapon and apply the +1 two-handed bonus to the weapon. This allows him to carry a shield, a versatile weapon, and an off-hand weapon, or no shield and two off-hand weapons. Two versatile weapons are not possible since the secondary limbs have to be off-hand weapons, unless of course he takes the Two-Blade path of the Ranger class. He may use also choose to use three limbs on a two-handed weapon, and will likewise apply a similar +1 bonus. This would effectively allow him to wield a two-handed weapon with a versatile bonus and a shield. For Thri-Kreen with multiple weapons, once per encounter he may make two basic attacks, once with the main and once with an off-hand applying Strength bonus to both.”
I also think that to take advantage of the Thri-Kreen’s unique physiology, the gythka can act as a double weapon, with each side allowing a versatile bonus, but only for creatures with more than two-limbs. Other races would have to use it as just a double weapon with no ability to use the versatile bonus of one end. So a normal Thri-Kreen could wield a shield and a gythka, apply versatile bonus to one end, and off-hand the other. A Thri-Kreen ranger could versatile bonus both ends and remove the shield. This would let Thri-Kreen make the most out of how most powers limit characters to one attack, and still be able to make the most out of the two-weapon powers of rangers. Plus, I don’t think adding a +1 damage bonus to two-handed weapons would unbalance them, since that +1 damage bonus isn’t applicable to weapon damage multipliers.
Also, will the Thri-Kreen be able to wear armor? They still seem overpowered if the can. Simply having to resize magic items doesn’t seem large enough a penalty, since it will only cost 175gp (I assume the price differences will be dealt with accordingly) to resize any magic item, no matter the level. I would think to balance against the high speed, multiple limbs, and venom that they would have to be restricted with armor to balance. The new system seems to shy away from taking away a race’s ability to wear armor, though. I might be mistaken on this, but what they have for the MM Warforged seems to indicate this.

On the subject of balance in D&D4 vs DS4 the simplest answer is usually true.
Thri-Kreen have multiple limbs, natural armor, and cant wear physical armor. done, no modifications are needed.
With these 4 limbs a Thri-Kreen can do ANYTHING 2 humans could do if they were standing in the same place. The feats or class features are still needed to include the training for multiple weapon use, when a class feature says 2 weapons it means 2 weapons, so usually wielding 4 melee weapons looks cool but is fairly dumb. Optimum functionality is either 2 2-handed weapons for or a single 2-handed weapon backed up by two shields (that balances out the lack of heavy armor).
If we want to get into race specific paragon paths we could set up a 4 blade Ranger Thri-Kreen but I would be inclined to think that falls in the ‘uncalled for’ category. As for unarmed damage, its got daggers on the end of its hands and can benefit from any combat action as if all its unused hands counted as light blades.
Give it the poisonous bite as the racial feature and the feat long jump, take away the common language, so anyone playing a Thri-kreen gets the long jump feat, but needs to take the language feat to speak the meat languages (rather appropriate for the setting) and again you solve a balance issue.

Well, the lack of armor for Thri-Kreen is a bit more unbalancing than it used to be since armor is basically the only thing that can be enhanced to boost your AC. Shields can no longer be enhanced in such a fashion, so being allowed to use two shields seems reasonable at a glance, but this leads to exceptionally well armored Thri-Kreen at early levels, and exceptionally vulnerable Thri-Kreen at later levels. This is taking into account that the people at Wizard are probably expecting us to use the superior materials at later levels as well. So we’re losing around 8 AC for light armor users, and 12 AC for heavy armor users (although I doubt people would take heavy armor for Thri-Kreen anyway), for a trade off of an extra 2 AC for one additional shield. I think using three shields is also pushing it too far. I would probably be too cumbersome to fight effectively with that much material in your way.

Humm, since a lot of race in Monster Manual don’t have Natural Armor now, I think the best way to handle it, it’s armor for Thri-Kreen available & NO Natural Armor at all. So now, no more problem with natural armor or not.

bengeldorn: Your entry is too much much powerful, maybe too much 2E. I like your Thri-Kreen Feats.
Natural Armor have been drop in 4E, we will see thri-kreen in armor i’m sure (like Warforged and other Monster PC). Extra attacks have been drop in 4E also (except with action point). Any unarmed combat do 1d4 now, but i see only a +1 with claws not +2. Proficiency with Gythka and chatkcha?. +2 in Athletics cover their better jump so no need to give them another bonus.

The idea was, that the natural (I didn’t call it natural btw.) armor bonus doesn’t stack with other armor. So basically Thri-Kreen are treated as allready wearing an armor. You could other armor, but unless it doesn’t provide at least a +4, it wouldn’t have any effect (regarding to AC). Besides several monsters in the MM have some kind of armor. It just isn’t named any more.
The extra attack was taken from the MM, with a little Modifikation. So basically, there still are extra attacks. But I was allready considering to change the entry to something like this:
Multiple Limps: Thri-Kreen have four arms. When you attack an enemie you have combat advantage against, you can make a extra basic meele attack against this enemy, but with another weapon (or weapon end).
IMHO the claw attacks should be more dangerous than unarmed attacks of common humanoids. Maybe +1 is enough. Maybe the claws should be in a different weapon group. I don’t know….it was just an idea, I toyed around with.
The reason why I gave Thre-Kreen the Long Jump feat wasn’t entirly because of the +1 bonus, but to give them the ability to jump without a running start.
As for the balance issue.. well other races have at least one racial power from the start, my Thri-Kreen version doesn’t (although you could consider the extra attack from Multiple Limps as a Power). There has to bee some testing to see, wether the Thri-kreen is balanced or not.
And for the Thri-Kreen Weapon Proficiency: You gain proficiency with the gythka and with the chatkcha.
;-)

4thed Seem to favour much simpler mechanics. I think the multiple attack madness has been reduced a lot.
So i really dont like the multi attack cus i have many arms angle. Mebbe some other type of bonus is preferrable.
In 4th edition the races tend to go like what follows:
Ability scores: 4 bonus in total
Size: Medium (usually)
Speed: Dwarf = 5, Efl = 7 , The rest = 6
Vision: Normal (usually , lowlight on some)
Languages: 2 different Languages
Skill Bonuses +4 bonus in total
Racial Abilities: 3 different Abilities on average (Some have more)
Example: Dragonborn have Dragoborn Fury, Draconic Heritage, Dragon Breath
With this in mind it should be a simpler matter to balance all the races surely?
Thus off the top of my head:
Thri Kreen
Ability scores: +2 dexterity, +2 wisdom
Size: Medium, but occupies 2×1 squares
Speed: 7 (Traditionally they are represented as fast in 2ed)
Vision: Normal with antennae ( Reduces the effects of sensory deprivation in 2ed)
Languages: Kreen, ( One less language frees up extra “points”)
Skill Bonuses: + 2 Perception, +2 Nature (Being from a hunter culture)
Racial Abilities:
Never sleeps:
The Thri Kreen Have no need to sleep, and consider it wasteful.
Multiple Limbs:
The Thri-Kreen Gains a free extra minor action a round.
Venomous bite:
A thrikreen’s saliva is venomous: Gain the Venomous Bite Encounter Power
Encounter power: Venomous Bite (Minor Action)
Attack: Dex+2 vs. Reflex.
Hit: 1d6 + Constitution modifier damage.
Increase 10 +4 bonus and 2d6 + Constitution modifier damage at 11th level, and to +6 bonus and 3d6 + constitution modifier at 21st level.
Special: The poison disorients the prey granting a -2 penalty on all actions untill a succesful save vs. Con is made.
Powerful Leap:
All leap distances involving a Thrikreen are doubled.
The extra distance gained does not count as part of your movement, and does not use a part of your move.
Wild Talent Feat: (Mechanics to be determined later, all races get this for free.)
Racial Feats: (Taken later in Character progression, some may be taken at creation)
Tokchak: (clutch mentality or “egg-mind”)
“Without a doubt, the most important aspect of the thri-kreen
psychological nature is reverence for the clutch and for clutchmates.
This shapes kreen behavior at all times, even when not
among clutchmates.” – Thri – Kreen of Athas
The Thrikreen Character gains +1 to all actions in combat when fighting adjacent to a clutchmate.
+2 I the Thri-Kreen has combat advantage over the target and it is an attack.
Tikchak: ( ““hunter-mind””)
“Like the clutch, the hunt shapes the thri-kreen lifestyle. Not only
do the thri-kreen hunt to survive, but they carry the mindset of
the hunt (tikchak, or “hunter-mind”) into other aspects of their
lives. Much of a thir-kreen’s normal day is spent preparing for
the hunt, hunting, and preserving food and doing other things in
response to the hunt.” – Thri – Kreen of Athas
Thri-kreen Character Gains +2 Stealth and +2 Initiative.
Cultural Arms:
While weilding A Gythka, Chatcka or using your natural claws you gain +1 bonus to attack.
The thri-kreen may use a shield while weilding a two handed weapon.
Not sure how balanced everything is but im jus fooling around. Getting ideas together.

As Thri-Kreen are a particular favorite of mine, and game balance of great interest to me, I find myself in a bit of a bind, as the Thri-Kreen have never been a balanced part of the system. With the social and political limitations on the race used as the primary balancing agent, that is no longer sufficient to pay for as much power as the race once had, although I think it should still buy them some flavor.
The first thought that must come to mind is 4 arms, and how they work. The multi weapon combat rules for 4e are considerably less powerful than 3.5 in the sense that all multi weapon attacks require a class feature designed to implement them. I for one see no reason to change this. The advantage of having 4 arms is enough, you can still do the same things your class would normally let you do, with the obvious changes. 2 weapons work in many ways, a pair of one handed melee weapons and a shield, leaving a hand open for a ranged weapon or spell implement. A pair of two handed weapons used with all the two handed weapon advantages by a ranger with two weapon styles. Or even 2 one handed weapons with a two handed ranged weapon, ect.
The key is you can’t get around the system limits, like 1 shield, 2 attacks, action limits, that sort of thing, just that you have more limbs to switch around between however you want.

How about use the Eladrin as a base for the trhikreen?
+2 dex +2 wis seem ok.
6 move and low light vision seems fine too.
Tweak the skills and languages
The Fey Step racial can be the thri kreen’s leap ability as they leapt further in 2ed.
Eladrin weapon proficiency becomes thri kreen weapon proficiency.
Trance = no sleep.
Eladrin will can easily be applied to thri kreen as the have completely “alien” biology/minds and are resistant to using magic.
Remove Fey origin from the list of abilities along with Eladrin Education and replace them with something more kreeny.
Any ideas?

Oh and add all the other stuff:
Extra pair of arms/attack, Venomous bite etc, later with racial feats.

Sounds pretty good, although I’d increase the speed by at least 2. In 2nd edition, Thri-Kreens were 1 1/2 times faster than humans. In 3rd edition they were slowed down to 1 1/3 times human speed. If the Thri-Kreen will get a speed of 6, it’ll become slower than an Elf (speed: 7).
In addition I’d suggest to provide an AC-Bonus, because one of the (many) Thri-Kreen features is their natural chitin armor.
I agree on making Venomous Bite as a feat. Take a look at my proposal about 10 posts above yours.

Use the 2 speed increase to replace the eladrin education and fey origin. I would also suggest making the leap require line of effect (not just line of sight) and be a length equal to the current move rate (even if they take feats or use magic to raise the speed, the jump goes up) that should just about fix them.

Guys, check out this attempt at stating the kreen as a PC race, and the 3 kreen monsters he created (pages 6-7 of the PDF): http://sites.google.com/site/silent7seven/Home

I have a list of comments first off the monsters are built a bit wrong, they have low stats HP and AC, but to many and to special of powers, to many features for monsters.
As for the race itself, the major errors are the Telepathic language and the attributes for the weapons, the Gythka is missing something, either a +3 prof bonus, or a special feature, something like ‘counts as two weapons’ so you get the +1 damage for having a second weapon equipped. The Chatkcha is listed as a ‘light blade’ and a ‘heavy thrown’ weapon on a +dex race, has a lower bonus and less range than a shurkin. Call it a +2, 1d6 high crit weapon with a 5/10 range that ‘returns’ so it doesn’t count as lost amo when you don’t hit. (hits are retrievable normally)
I do like the ‘multiple limbs racial feature, that is exactly what I was looking for, although a little more clarity on ‘hold more stuff’ could be nice, it is possibly better left vague for players to figure out, perhaps a comment that the Thri-Kreen can benefit from each different type of equipment it wields just as someone with two hands would, only with more options.

I’m not familiar with 4thEd rules. so bare with me for a moment
With the rule makers and multi-weapon attacks, they tend to forget at times about creatures with more than two arms. so most of the rule cover TWO arm creatures and not four or more. they are born with four (or more), so why would they not know how to use all of them equally as well. they many favor one side, so be it. it would be like any two arm creature, whether it is a lefty or a righty.
If nothing else, they would recieve negatives if they were incapable and/or lost one or more arms.
all of you are so worried about their bonuses that you forget their weaknesses. like, age- they live up to 30 years. they start adventuring at 4-6 years old. any aging affects is serious to them. they respiration is thru their skin, so they can’t hold their breathe. any gases and dust attacks affects them automatically and drowning occurs once their body (not head) goes underwater. hence fear of large and/or deep bodies of water.
as a DM in 2ndEd, I applied negatives to saves vs. gases and the like. and to me, they are not a medium size creature, six ft. in height with an over all length of ten to twelve ft., THAT is a large creature.

Interesting ideas here. I think this race will be the toughest to convert, and it shows some flaws in the design of 4e, especially natural armor and multiple weapon fighting (the former having no mechanical acknowledgment and the latter having weird consequences in 4e.) Lets see.
What makes a thri-kreen a thri-kreen. Its an insectoid humanoid, has 4 arms, an exoskeleton, makes great leaps, doesn’t sleep, wields strange weapons (mainly gythka and chatkcha), paralysing venom, focused on hunting, has trouble relating to other humanoid races. You could also add the speed, reflexes to dodge missiles, the antennae, the clutch mentality and the ancestral knowledge it has.
Hmm… lots of work…
Insectoid: The resizing element for items is a good idea, even though its sort of a penalty, which 4e doesn’t like. It still seems necessary. There isn’t an insectoid type or keyword, except perhaps aberrant, which sounds wrong. Aberrant humanoid?
4 arms: The easiest war to go is simply make the 4 arms able to hold 4 things at the ready, as some suggested. Using extra weapons effectively should be racial feats, and thats it. As for the 2 shields bonuses, I’d think they won’t stack, but that’s a good question: What happens when a human uses 2 shields (2 arms, right?). I’d think it wouldn’t really be practical, in any case.
exoskeleton: First major problem with 4e. If warforged (read humanoids covered and made of wood and metal plating) don’t get armor bonuses and get to wear armor, I hardly think thri-kreen will get natural armor. I’ll have to go through the books and see if there’s a precedent for it.
In any case, I was thinking of making my future eberron warforged characters required to purchase and keep their first armor as their initial plating. They can’t change armor on the fly, but they get to keep it all the time. They can enchant it normally, though they have to be part of the enchanting ritual (even if just as the material) and can remove it as other components to “upgrade”. However, this would mean they can never benefit from looted armor, I know. But this is an occasion where rules trump setting reality, always a bad thing.
We could force thri-kreen to purchase and keep a “exoskeleton armor” in the same way I guess, and make it enchantable. But we’ll see.
Leaps: A bonus to athletics seems a poor substitute, and would pretty much require thri-kreen to be trained in the skill to benefit from their racial ability. An ability akin to that presented by pennarin might be better. I’d even put it as similar to the eldarin teleport power, but since its not a teleport (and thus can’t be used instantly and easily in interior settings and can’t pass through some barriers), I’d make it a move action, but maybe an at-will power (they should be able to leap continuously, although it could be scaled down to Encounter, justified by exerting the race).
No sleep: Just have them relax for 4 hours, a bit like the trance of the eladrin.
Strange Weapons: Proficiency with gythka and chatkcha. Don’t make those too good though, since that would make the racial ability too good.
Paralysing Venom: This would be the core racial ability, a bit like the dragonborn’s breath. Something like an encounter power. Melee. Dex. vs. Fort. Target is slowed. If save is failed target slowed and immobilised. If second save fails, target is paralised (helpless) (save ends all effects). This would make it potentially lethal, but hardly overpowering. Once per encounter, you get to slow an enemy, maybe stop him, and have a chance (after 2 rounds) that he paralises. Feats could increase potency.
Hunting: +2 nature. Not much, but a lot already.
Relating to others: No penalties, so hard to express correctly aside from roleplay.
Speed: Probably 7 squares.
Dodging arrows: Too powerful as core IMO. Make it a racial feat.
Antenea: Feats to help diminish blindness penalties and give perception bonuses? Or +2 Perception as other skill bonus (with nature)?
Clutch Mentality: An interesting idea for the bonuses with clutchmates someone had, but might be a good feat (we need to restrict core abilities).
Ancestral Memories: Another racial feat.
So, quite a list. That would be:
Thri-Kreen
Ability Scores: +2 Dexterity, +2 Wisdom.
Medium Size.
Normal Vision.
Speed: 7 squares.
Languages: Common and Kreen.
Skills: +2 Nature, +2 Perception. (not sure about the last one)
Four limbs: You have four hands and can hold and ready 4 items in your hands. You do not gain any special bonus or ability for using multiple weapons or shields.
Exoskeleton: Need something here about armor and resizing items.
Kreen Weapons: Proficient with the Gythka and Chatkcha.
Doesn’t Sleep: You are immune to sleep effects and do not require sleep. You may rest for 4 hours while remaining awake and gain the benefits of an extended rest.
Leap: Racial Utility Power. Encounter. Move action. You can jump up to 5 squares horizontally and 2 squares vertically, or 5 squares vertically and 2 squares horizontally. You trigger opportunity attacks when using this ability, but only from opponents adjacent to you on your starting square.
Paralysing Venom: Racial Ability. Encounter. Standard Action. Dexterity vs Fortitude. Hit: target is dealt 1d4+dex damage and slowed (save ends). First failed save: Target is immobilised (save ends). Second failed save: Target is paralysed (Helpless) (save ends).
There. What do you think?

There was nothing keeping kreen from wearing armor in 3e. The only rule about it was that armor sized to monstrous humanoids cost double.

I like most of what you have set up, there are a few suggestions I would like to make, and perhaps a few clerifications that you already have in mind.
First off both skills rather than just one.
Second One racial power not two, perhaps the ability to pick which one you get and a feat to unlock the second?
Third the Paralyzing Venom needs to include the 1d4+dex as its damage listing.
Forth Speed 8 is more appropriate for the Thri-Kreen, even though it will hardly ever matter.
Finally the question of armor, this is the difficult one to be sure, I for one do not see why Thri-Kreen can not use all the regular attributes for armor although constructed in a different shape, requiring non standard craftsmanship and limiting the usability of ‘looted’ armor can be seen as limitations but they are minor limits in trade for the list of advantages available to this highly specialized race. On the question of shields, I could see a feat that works for two shields, one on each side, perhaps named “Phalanx of One” that gives you a +1 AC bonus if using two shields of the same type.

Aran,
In athas.org’s version, you are correct. Mine had different mechanics, which I forgot were not in the final version of athas.org.
hendell,
Thank you for your suggestion and clear feedback.
First, I wanted two skills, I’m just not certain about making the second one Perception. Stealth seems innappropriate, even if they are hunters, and halflings or elves might get it. Any other ideas? Don’t have my PHB here now.
Second, I really think both abilities should be there, but is it really overpowering? The drow have multiple racial abilities. I think neither is that overpowering. The thri-kreen probably can simply move to most places it leaps to in combat, and the venom is hardly very powerful. No?
Third, You are absolutely right. Is Dex really the right Ability here? I was thinking Con for the poison, but the damage isn’t from poison but from the bite. Would need to look at some poison abilities to make sure of the mechanics.
Fourth, speed might be 8, but I’d keep it at 7 since it already has many good abilities and would still be above average (only the elf would match its speed)
Lastly, on armor, the feat idea for shields is interesting, but as I’ve pointed out, I don’t think any race gets a better bonus to AC from using 2 shields, and most could do so with 2 arms. The exception might be something akin to tortoise blades, but that weapon would probably have exception rules for shield bonuses. As for wearing armor, they could, but they still would have a natural armor with their exoskeleton, and other armor would really need to be custom made for kreen. Maybe double armor cost for them and resizing for magic armor? I still don’t really care for thri-kreen wearing chitin armor…
In my conversion, I allowed kreen to wear armor, but they could never gain armor proficiency feats, since the armor always felt akward to them, and thus they applied check penalties to attacks as well as most physical skills. That worked fine. Not very 4e though. Will need to rethink this I guess. Thanks.
Edited Thri-Kreen build to include dex bonus to damage from venom bite and clarify opporunity attacks on leap ability.

The Drow do indeed have two racial powers, although they are limited to only using one of them per encounter. The Drow powers are of a like ‘type’ so there is some logic to one draining the power the other would have used. The Leaping function and the Poison could both be seen as a draw upon the ‘martial’ power supply of a Thri-Kreen in much the same way, and thus a feat letting each be used or even a second use split or doubled up as needed like the Drow feat that has the same effect in the players guide to Ferun.
The question of the skills is a good one as well, I see no reason why perception must be a focus skill, although its obvious biasing link with a wis bonus does seem tempting I could see Athletics being just as appropriate, or even endurance to represent the lack of any need for sleep.
The Chitin exoskeleton of a Thri-Kreen has never been exceptionally tough, at its best accounting for the equivalent armor value of chain mail, while nothing to laugh at it hardly makes or breaks anything. Some of the versions of Thri-Kreen have played down the Exoskeleton’s toughness more into the range of leather armors, little more than toughened skin without nerves and blood vessels.
I think the blanket removal of Natural Armor in 4e is an acceptable loss of ‘logic’ in trade for system mechanics but that point is irrelevant, the fact is that we have to assume at least some of the people (perhaps the target audience) of any 4e Dark Sun supplement have no idea how Dark Sun was in 2nd or 3rd edition, and should focus on internal system cohesiveness in the most ‘thematically cohesive’ way, our objective being to make a great world easily accessible to a system that lends itself to the high violence high danger, high combat setting of Dark Sun.
To that end, much like the Warforged, the Thri-Kreen must assume its Chitin Exoskeleton is no more inherently durable than the Human Endoskeleton and plan for that. I like the idea of ‘hardening agents’ being applied to the Chitin directly, much like the piercings and tatoos that show up in some 2e flavor text. Between that and a sort of piece mail armor more like barding I see no reason a Thri-Kreen couldn’t just buy armor, at double price in non Thri-Kreen civilization, but at normal price in the Thor-Kreen nation for instance.
The various ways of using 4 items in 4 arms should be enough to justify the extra hands, the real point behind the Thri-Kreen is its flavor, not its power.

We could always make the protective chitin another racial feat, something like ‘Hardened Exoskeleton’, or even just ‘Protective Chitin’.

incidentally, as for a double shield bonus for carrying two shields, I would say yes and only if they carry one shield on each side. ei. one on the lower right arm and one on the lower left arm. but they would have to be small or medium in size.