I have gotten great advice on this forum before and am coming back to the well. Thanks for all the help in previous setups!
Moving into a new place that will have a (not huge) dedicated HT room. I've included a schematic of the room in this post, below. It's got a window that juts into the room a little and a projector screen that covers said window. It also has a large sofa that is unfortunately non-negotiable and will have to sit in the corner as shown. There's a projector in the ceiling that has good image quality.
I want as many speakers as makes sense. I have decided to go either in-wall or in-ceiling for any rears or surrounds, since we are doing a bunch of drywall work anyway. My hardware can handle 7.1 and I'd rather not upgrade it.
So my overall question is this: given the decisions we've already made (and on which I really don't want to have to go back) what's the best way to set this up for HT audio? Not looking for brand recommendations right now - I'm hoping for recommendations on room acoustics primarily. Once I make a call on that, I will focus on which speakers to implement into the plan.
My sub-questions:
1. If you were going to put 4 rear/surround speakers in, where would you put them? All in-ceiling, all in-wall, or a combination?
2. How much better will 7.1 sound than 5.1 in this room? If I have 4 rear/surrounds in that close a proximity, will they all kind of talk over each other and get muddy? Is there a speaker technology (monopole, dipole, bipole, etc) that would mitigate that muddiness?
3. I have enough room for L/Rs since there is a lot of space on either side of the screen / window. Can I mount the C speaker to the wall? If not, should I consider in-ceiling L/C/Rs as well?
I know this is a lot of questions and I thank the community in advance for any help you guys can provide. I live in Los Angeles and if anyone has a good recommendation on a professional consult, that would also be much appreciated.