i dont think 60 is the limit, heared of complex weapons (errantAI as far as i remember) using far beyond 90.
there is a working human boning system for blender>fpsc anywhere around here (i think posted by starmind). you need a basic bone called ROOT on 0,0,0 and for using weapons a FIRESPOT. so far its working for unarmed characters. i get an error / crash when using nonhuman bone-structure with weapons, but i changed animation-numbers and frames and alter a vweap, maybe the error is there, maybe its an error in the characters x-file or fpe or i missed naming/bone-order anywhere, i dont know but wish someone experienced is answering your question in detail.
good luck^^