I thought that it would maybe detract from the clean look it currently has.

If you use a mask it won't be a problem, just think of how dirt builds in the real world and create a mask for it. For bricks a inverse AO texture works.

I was actually wondering if adding in rugs, maybe some chandeliers, and a little bit of variety on the architecture would be of use as well?

Could work but don't over do it, creating too much details just makes the scene noisy and takes away from the objects of focus.