I think it would be good to move the ep500 like you suggested... HAving them at midpoints on opposite sidewalls is supposedly an ideal configuration... I would just do som experimenting.

You could hang the rear surrounds from the ceiling with some ceiling mounts that don't allow them to stick down much.

I think 17' is too far IMO, but I have never ran a 7.1 (or 2) setup (just 5.1), so that is just a guess.



-David