i like all the rest of it but his attack animation just looks like he's trying to stab himself in the shoulder with nothing in his hand. his head moves weirdly in that anim as well. also if you look from the side he's leaning into nothing. he looks like he should fall over because he's got both feet parallell and behind his center of gravity. one foot is always in front in any kind of fighting stance unless you're handling a static machine gun.
edit to not come off negative, let me say that the model is very cool looking. i wouldn't bother giving suggestions for improvement if it wasn't promising.