I guess it coul work without lights and just the env map (or maybe an ambient/hemi light, so no shadows), however I do see the 2 issues above even without lights.
As for the model, I have little control on it, as it comes straight from the game and it will require to keep the UV intact so that decals layers can fit correctly. I am not experienced in blender is there a way to reduce triangle count while keeping UVs intact? @felixmariotto