Personally I would make the "public" part of the apartment (Livingroom/kitchen...where I might be entertaining) larger and the "private" part (bedroom) smaller. I would probably make the bedroom big enough to accomodate my current bedroom set with some space to walk around the bed, but no more than that. I wouldn't be getting rid of the king bed either, especially if your DH is a big guy. Same with the bathroom...I'd make it a normal size bathroom but it doesn't need to be massive.
Other than that, the ideas PPs have given you are great!