Ah, sweet stuff! This is really interesting. ^^
What I wanted to do was make a sort of troll sniper(with the Rifleman\Marine\Space Orc animations, although I'm more leaning towards the Rifleman at the moment), who can "Morph" into an alternate form where he crawls around(à la Headhunter), but is unable to attack. So a mix between the middle one and the right one on your image would be the best, I think. Of course, I'll have to patch up the animations so that they aren't so screwed up(Death, for example), but otherwise what you did is perfect.
I'd love it if you could make a tutorial about doing stuff like that.
Oh, and out of curiosity, how long did each of this take you, approximately? And how difficult would it be to repeat what you did, assuming I know more or less how your program works? ^^
P.S: ...By the way, would it be possible to give the Headhunter marine upper body animations? I think, at the moment, the headhunter's aim is a little bit off.
(And if possible, would it screw the model up too much?)