So I looked around for feats that would allow a Thri-Kreen to legally use their middle arms because:
"The middle set of limbs is small but dexterous, and the thri kreen use them for fine manipulation, leaving heavy work to the stronger upper arms. Both the middle and the upper pairs of limbs have three clawed fingers and one opposable thumb. In combat, thri-kreen hold weapons or shields in their upper limbs, since the middle pair lacks the strength for this purpose and using both sets of limbs would be awkward and unwieldy." [Dark Sun, pg22]
Although these arms are small and dexterous, but lack the strength to fully manipulate a weapon, to make an attack, they can still perform fine manipulation (i.e., draw or sheathe a weapon or retrieve or stow an item stored on your person)
Now, what if I use the Wild Talent Feat Telekinetic Grasp:
One object that weighs 20 pounds or less and isn’t carried by another creature.
Effect: You manipulate the target or move it 5 squares to a square within range. [Dark Sun, pg81]
Would this combination allow a Thri Kreen to make an attack with something as simple as a dagger while in combat? If you agree then would this attack be a melee basic, At-will or encounter/daily? and because of the wording, would it use dexterity or the at-will ability?