In answer to your questions:

1) Sure, it has to fit your situation so we make do with what the best compromise allows;
2) Not sure what you mean, use of the HTR 7000s is all about eliminating hot spotting from close proximity overhead speakers;

Regarding rears, you can only do what the situation (or significant others) allows. We were quite pleased with the results of using Triton Twos for surrounds (5.1) in our Atmos demo setup.

Always good to ask all the questions before you start cutting holes and running wires.