Texturing Walls and objects

[SacSurfin']

I've noticed that objects and walls texture differently. Sometimes to cut archways in walls it is easier just to draw a shape and cut it out, but when this is done and rendered the solid subtraction looks nothing like the walls, it's rough and wavy. Is the only solution to stop using solid subtractions and stick to nothing but walls? I've learned alot since my first elevation and currently can figure out how things are done using walls, but draw and cut is just faster.