OK, I think I'm zeroing in on a final plan:

The cement plant had to go. Even though it doesn't have a large footprint, it's over 7 inches tall and would end up dominating everything. I doubt the mountain itself will be much taller than that. I replaced it with the much lower profile propane station, which allows for some switching while not distracting from the coal hauling theme of the layout. I also brought mine #2 back onto the other side of the hill because I didn't want both mines visible from the same side, and also it would look a bit strange being situated almost right on top of the downtown area.
So unless there's some major problem I'm overlooking, it's time to find a 36x80 HCD.