Thoughts on this stuff:
Sheep and/or Fear from warcraft. As a warrior who was sheep/feared/sheep/feared/sheep/feared over and over again (and again and again) in the BG's, I am officially giving you the bird for that suggestion.
As for the specific body part damage - who's going to hate me if I say: I really like that?
As for the signature attacks - I thought that was kind of cool on DBZ as well. In fact, once upon a time - Farnite and I were talking (seems like we talked about ideas more than we implimented them) about having 2 or 3 customizable ones. Either making them completely customizable, or just renaming an existing spell. Ie: you can rename 2 spells, so a shield spell becomes Devinoste's Barrier or a backstab can be seen as Glith's Ribtickler or whatever.
The other idea we had bounced around was like at the end of tier 2, at level 100 (or at level 150 when reaching end of 3rd tier, etc - and each one was 'stronger' than the last, so you could make 3 buffing spells, or 3 attack spells or 3 attack skills...) - you get your choice of 3 or 4 types of spells. Attack, buffing, creating, whatever. Then you could configure it to be named what you wanted. Then you could set it to buff one of a few set fields (ac, a stat, hitroll, damroll for buff spells, type of creation - food, potion, scroll or attack type - damtype: water, fire, acid) - and they are all set to values already. So this spell would either improve AC by 25, damroll by 10, hitroll by 10, a stat by 3, do 75 points of damage on average... etc. So it all looked very customizable, but basically it was all referring back to a basic structure of stuff, and it was automatically 'grand mastered' there was no improving it, it just sat at 100% all of the time, etc. But, then he decided it was over his head and it got nixed.