Is there any reason not to use the other wall (the right wall in the diagram) as the main wall in the HT setup?
It seems as if it would save you a lot of trouble, since you are building one there anyways.
Honestly, going through the trouble of running some cables a few extra feet for power and what not is definately going to be worth it in your situation. Putting the screen on the wall you are building will make your screen actually centered in the room without being off center, and you won't have to deal with beating yourself up about deciding what to do.
Just a thought :-)
Good luck with your HT, that is a very nice room for it, looks great!
