I have a WIP projection-based HT that's a little bigger than 10' W x 16' D x 8' H, that I'm now realizing is a tad small as I design the electronics and seating.

a. I'm debating if the L/R channels should go behind the screen (either they'll be too close to each other, or too close to the side walls).
b. I'm thinking the center channel has to go behind the screen for the best visual appeal, but I want don't want to build a huge false wall and make the screen even closer to the viewing area.
c. I'd like 2 row seating, which might be blind row 1 even on a 92" screen, and row 2 will have to be right on the back wall.

Here's what I'm looking at acquiring:
L/R: M22 in-wall/on-wall hybrid's
C: ?? hybrid something -- M2 VP100 M22 VP150 -- whatever matches best and fits the room size
BS: none -- I assume LS/RS QS8's will get it done, and I'll gain nothing sitting right on the wall
PLIIz: M2 hybrid's if they will add effect, else none
Sub: reuse a Velodyne monster circa 1994.
Receiver: Onkyo TX-NR609

1. Will it sound that much better going behind the screen to align the L/C/R tweeters?
2. Which C speaker?
3. Should L/R join the C behind the screen for acoustic reasons?
4. Will I miss being able to toe-in the L/R based on room dimensions?
5. Should I bother with back surround channels?
6. Should I bother with front height channels?

Also, is there any thought of M60 hybrids? Perhaps that would be overkill for this sized-room, but I own some 2-way bookshelfs and 3-way floorstandings today, and can obviously hear a difference. Thanks!