I think that any AVR running at half power will be hot to the touch, 96* f is not bad but I've run it hotter and without concern, really. I just wouldn't go,,,say 110 * all day long. Does your AVR have pre outs? If so this would afford the possibility of an external amp in the future. For theater you should be fine.
With you doing 75% HT I would not take the center that goes with the towers!!
I would invest in the best and largest center speaker that you can afford.
For this reason,,,,,,,,the most heavily used and inportant speaker in a HT setup is the center channel!!! PERIOD!!! All spoken words come from it ,,,and if you own a poor center you will not understand the dialog !! Isn't that where most of the story line comes from??!! YEP Please heed this advice, I've seen so many systems fall short do to this fact. Surround sound and crashes and all sort of information comes from all of the other speakers,,,,but story and dialog come from one source,,,,,
THE CENTER CHANNEL!!!!
Can I beg you not to short change that speaker!!!