Yes, but you may find it very very hard unless you live with dynamic entities, or make everything in a per texture mesh and fit together in game like LEGO.
I say this as you have (as far as I know) zero control over the UV Mapping, as it is a CSG modeller and uses texture tilling. i.e. lots of separate textures, where as fpsc as a rule requires a single texture per mesh unless the mesh is a dynamic entity which can use multiple textures (if I recall correctly)
This is not to say you should not use the program (especially if your happy with it), just that you will have to think on your texture usage whilst modelling is all
Your signature has been erased by a mod. The sig needs to be 600 width maximum (x 120 height) for all of it.