[RWebb]

I'd worry if I had a high-end stereo - injection of RF noise can degrade the sound quality.

A friend ran CAT-6 all over his house - IIRC, he did it all just with drilling holes, no big knockouts of drywall (OTOH, he handles electrical work for a local college). But you may find a fast wired connection is not much trouble.

WiFi is about to get a bump up in speed, so the a/c spec. is worth investigating. Wait a while longer and there should be WiMax.