Movies and TV are 60% center channel, 35% subwoofer, 4% mains+ surrounds, 1% everything else.
So as long as the center and subwoofer are beefy and optimized flat, then the overall experience should be pretty good.
For the center channel you may be worried about floor and/or ceiling reflections, sidewalls are unlikely to impact the front row.
As far as 2-ch music goes, sure... restricting the mains is probably the last thing you'd want to do from a soundstage/imaging perspective, but it won't really impact the SQ too much.
You are probably worrying about it more than you should be.
For movies, you'll be the only person that notices it... trust me when I say: the wife, kids, and friends probably won't notice (so don't make it known, ignorance is bliss...)