Yep, like this http://imageshack.us/scaled/landing/227/exampleofwallswk0.jpg It certainly isnt the only way to do things, but it helps with modular env construction
This looks great already :) Very modular. Also like the grid. Are you doing anything for the foreground? Right now it just cuts off. Or is that now in view?
You could put the accessories (optic, bipod, sling) on their own texture sheets if they're genuinely modular pieces that could be re-used on other weapons.