Can I position speakers near ceiling, as opposed to ear height?
I just setup a 5.1 system and obsessed a LOT about this. The room has 8 foot ceilings but has 4 foot knee walls on two sides (with a 45 degree run of sheet rock up to the ceiling). Placement in the corners was the "proper" location for speaker separation as well as aesthetics (and to keep kids from bumping into them). However, I was worried if I put the speakers in the corners I'd get a lot of harsh echos from the walls. In my case, yes I do get echos at some frequencies and it's obvious if a test blip is played from that speaker alone, BUT when I'm watching a movie I don't notice it at all (the speakers were the rears).

What I'd suggest is to try out the speakers on temporary mounts near the ceiling if feasible (command strips or the like depending on how heavy they are). If the "voices from heaven" effect isn't a problem, then you're good.

In my setup the fronts are essentially right next to the TV and I find I still get enough stereo separation for me. So keeping them nearer the TV but closer together likely wouldn't be a problem either (especially if having them high is distracting)