Your setup is very close to my own, though i don't have that unfortunate bulkhead to deal with. The one thing that stuck out to me was your intended projector mounting position. The bottom of the projector looks as though it would be knocking a few heads! I have a 7'9" ceiling height and intend to mount the projector as high as possible in the back of my room to give the most head clearance i can. Is it possible you could do the same? Max throw from the lense to the screen is about 20' i think for the 8700.
Give the increased distance, i bet the projection beam would miss the bulkhead !