Hi, I don't have much time right now to go over this whole thread, but a couple of little offerings:
If you can have any kind of curtaining, or something, you can make a small hole at the ceiling, or slanted part, and drop the wires. They can run behind the projection screen. Or perhaps you can build a false wall. That would be nice. Wouldn't have to worry about wires nearly as much.
I presume you are budgeting for treatments. It's virtually impossible to go overkill with bass trapping. If you think about it, if you properly treat the room for reflections, you will be given more freedom in speaker placements. Because with untreated walls, you will more likely position the speakers with the room's reflective properties as an important determining factor.