Brian - I'd love to see your layout someday!
Regarding the question on lighting Dept. 56 structures without the glow coming through the walls, this can be accomplished using 3-volt light bulbs controlled by a dimmer switch, or variable transformer throttle. Sometimes though, it's neat to see the glow through the structures.
My former layout, which started as a seasonal Christmas pike, featured about 50 or so Dept. 56 and Stoney Express ceramic/percelain buildings in a multi-tiered semi-hi-rail/toy rail setting. Jim Barrett photographed the layout a few years ago, and although I haven't seen the pictures yet, if it hasn't appeared by now, I am doubting it'll ever appear in OGR.
My new layout (island shape in center of basement) plans call for mostly larger scale Railking buildings on the layout foreground, and concave-shape modules for the basement corners that will showcase our ceramic structures. The goal is a walk-around hi-rail layout in the middle of the basement and seasonal displays/themes in the corners with Dept. 56 Christmas in one area, Halloween in the another, and a Polar Express theme in the 3rd. The result will hopefully be a pleasant experience for all.