Heh, yeah. Actually, a lot of the stuff in the universe is bigger than you'd think; it's the size of the Chief that you see in comparison to everything else that throws you off. Spike grenades are like a foot or two long, the gravity hammer is colossal, Elites are giants, etc.
the first rifle... the one that resembles the m4, it's not too small, but the proportions are a little weird.
the bullpup design is cool, but the stock needs to be long enough to allow for the actual firing of the gun. as it is, you would have parts flying back through the butt. Try looking at the schematics for a similar gun, (Famas, AUG, Type 95, L85)
Everything else looks fine. i like your pistol a lot, and the uniform with the built in pads is awesome