Well, to answer some questions:
The ducts are about 4 feet wide. They will cause the ceiling to drop because of the sofft that will be placed around it. It makes more sense to me to put the seats under that higher ceiling because I plan on having an 8" riser for the rear row. If anyone stands up on the riser, they will absolutely bang their head on the soffit! So there is no option but to use that whole corridor as an aisle. where you can esily walk without hitting the ceiling (probably about ~6' 7" high altogether, because of the drop.
The door to the right is really just access to the electrical panel. We might make that just a smaller door panel, but either way, access to the electricals needs to be there. I hadn't thought of this before.
Any comment on the fact that with this arrangement, the posters would only be on the aisle side? I decided to remove them from the other side, because it seemed awkward to be sitting right next to these recessed boxes ont he wall... too much clutter and distraction.