I don't have anything useful on your TV set, but I'll comment on the surrounds. First, you're actually going to be using what are better called side surrounds rather than rear or back surrounds(back surrounds would be the 6th and 7th speakers in a 6.1 setup). Where side surrounds only are used, they should be, if possible, slightly behind the seat, rather than directly to the side, so as to give a bit of "back" effect. In your case the alcove makes things a little tight, but positioning on the sides of the alcove about 6 feet up and if possible a few inches behind you should work well. In any event the rear tweeters of the QS4s would give some bounce off the back wall, so the fore and aft positioning shouldn't be critical.
