I just thought of a good reason that kobolds couldn't use bows!
Okay, they could, but archery (IRL) takes a decade or two of training to be good at, and most kobolds don't really live long enough. Unless you're going with the vanilla maxage and not the old KC one. In that case, I'll stick to "Atlatls seem to fit kobolds better."
Yes, but kobolds are tiny. They eat meat. They cant just run up with a spear, can they? They must be trained from the second they hatch to use a bow.
Or...use atlatls.
I just thought of a good reason that kobolds couldn't use bows!
Okay, they could, but archery (IRL) takes a decade or two of training to be good at, and most kobolds don't really live long enough. Unless you're going with the vanilla maxage and not the old KC one. In that case, I'll stick to "Atlatls seem to fit kobolds better."
Yes, but kobolds are tiny. They eat meat. They cant just run up with a spear, can they? They must be trained from the second they hatch to use a bow.
Hatch? Did I mess up and leave [LAYS_EGGS] in? 
*Checks Raws* Nope don't see it in my current raws for KC.
And if people want even if it is a major setback, but make training bows really hard?
Maybe something like making kobolds learn bowboldship slower, but make bows stronger to compensate?
(Crossbows should be a bit stronger and easier to train then bows, but native kobold weaponry would train the fastest, and crossbows are hard to make.)
Yeah, I meant clusters of chippable (and diggable) stone to be mineable.
Also, I'd vote for kobolds being unable to draw human and elven bows, but being able to make weaker bows of their own.
Breaking apart foreign weapons seems suitable for spears and pikes (to obtain spearheads), arrows and bolts (for arrowheads), and maybe axes (so that the axe itself can be attached to a kobold spear to act as a kind of halberd) but it seems really weird to me regarding other weapons.
And how would kobolds break apart a steel sword?
And what use will the unliftable blade be for them if they can?
I'd say only spear- and arrowheads (and maybe axes) should be useable to make kobold weapons, with all the other foreign weapons only going into traps.
EDIT: maybe they should be able to modify the handle of a dagger to make their own kobold two-handed sword, but that's about all I think.
Even a steel sword can be broken by bashing it against a rock enough. The tip of a steel sword would make a deadly dagger, and the rest could be stuck together with a more maleable metal or with wire or leather or something to make armor or a shield or something.