1/ No, not particularly....low impedance speakers with the lesser avrs could be an issue perhaps at high volume with main zone also in use....maybe.
2/ Generally you keep power cords separate, but many have nests of various types that never cause any particular issue, too. Set it up as best you can and see if you need to worry about it further than that.
3/ I like smart power strips keyed to the avr and other gear....YMMV. Just what are your expectations of a power strip, tho?