>UAC has been out for awhile now. Are there any plans to add more regular critters that use UAC in its existing form?

Yes, but I have no timeline. Unarmed combat was designed to work with creatures from the beginning, mechanically, and I have test creatures that attack using it. I need to work out a proper AI routine for its use (I hesitate to abuse the term "AI" in that fashion, but it's the easiest short term to describe what I mean). I even have plans to convert a few creatures to using it. I'll have time to get to it someday...

>Also, is there any plan to expand UAC to accommodate critter attack forms such as clawing/biting?

No. Natural attacks will remain in the melee system (and most creatures that use those attacks are unintelligent anyway).