I'd check with Axiom on the supplementary baffle-thing. I suspect you're over-engineering it. Axiom speakers have very good off-axis response, so it might not be necessary. Also, I can't help but think that those kinds of baffles (besides being a b!tch to build!) would detract somewhat from the aesthetic you are seeking. I don't think it's a "standing wave" issue; I think it is a diffraction issue.
So, your TV is pretty high up, eh?
Where would the tweeters be relative to your ears if you mount the speakers upside-down? I don't see why this would pose any problem. As a matter-of-fact, I think that is a pretty ingenious solution to your wife's concerns.
