I have to agree with Tocky, the pose in this piece is really letting the rest of it down. I feel that at the moment the pose is too relaxed to be a shooting stance,
and too rigid to be an idle stance. Here's a rough idea of the kind of poses i'd use for shooting and idle stances respectively.
Other than the stance, I can only repeat what others have said. This'll be a bitch to animate at this size, and the pallette is gonna need alot of refining. But hey,
good luck with it, this could be awesome.