I was training and teching up an elf spearman (and elven war party) by killing kobolds (copper is infinitely better than wood) and noticed some oddities.
Firstly, even though kobolds can't use crossbows according to the entity raws, i found some kobold crossbowmen. They didn't actually have any crossbows or bolts but they did have quivers (better than a waterskin) which i put to good use.
Secondly, and vexingly, kobold archers have quivers full of copper arrows while living, but once they die their quivers and arrows disappear.
Later i went giant hunting for some human towns to build up my rep to recruit more elves and threw a *copper sword* i got off of a kobold swordmaster at a giant. It accommodatingly stuck in, along with a regular copper spear i threw. After killing the giant with the exceptional iron spear i had purchased from the humans with random wood jewelry from previous giants the sword and spear disappeared to my chagrin. I liked that sword...
I was using completely unmodded version of the game too.
To put it succinctly, the bugs here are the kobold 'crossbowmen', disappearing quivers/arrows on kobold bowmen, and the already known disappearance of stuckin weapons on death.
(Afterwards i continued to do merc work for humans but made the bad mistake of stepping into a human town near the elf forests. The first warning was the iron arrows thudding into my companions from the upper floor of the meadhall. The second one was the sheer amount of elf bone and leather bling the human bowmaster had on. Killed him and went outside to be accosted by two shopkeepers, also coated in elf wrought bling. Needless to say, i died.)
Another oddity i found by looking at the entity/site information was that many (semi)megabeast caves were also home to a single kobold each.
Kobold caves also became home to cougars and stuff which had gotten names in worldgen. This probably shouldn't be allowed.
Also, for some reason the giant cave nearest to the kobold cave had a bunch of kobold guards and civilians hanging around aboveground. I thought it would be cool if they were trying to settle a new cave, but i don't think thats what they were doing. I also got messages telling me how a giant cave swallow was ripping up a kobold bowman but was then pwned by arrows. Found the corpse too, it was inside the cave.