Hi JohnnyBeGood,
I'm not Ian but we tend to agree on most subjects.
On one hand, I'd say your system is only "too much" if you think it is. If it sounds great, then it ain't too much.
No, don't biwire. There is no scientific or acoustical evidence to support it, and I've never heard any difference whatsoever. If you want to try it, go ahead, but you can achieve the same end by simply using, say, 12-gauge cables, which will keep resistance very low.
I tend to think you may get too much bass emphasis with M80ti's in the rear corners, but every room is different. It's just that corners tend to give emphasize bass the most, and it can be somewhat uneven. If that's the case, move them away from the corners a few feet.
You might separate your M80ti mains by a greater distance but I don't know how far away you sit from them. I'd say 7 to 12 feet apart is ideal for the M80ti's, and the imaging is best when you're well back from them, perhaps 12 feet or more.
There aren't hard rules for the the side surrounds and rear surround placement--whatever yields the best sense of envelopment. But usually, multipole surrounds are more effective when they're further away (to the sides) from the listening area rather than closer. I like them several feet above listerners' heads, but since they're on stands, that's not an option. Experiment with them further away or a bit closer to the listening area.
Rear surrounds should be well back from your listening area, if possible. They should never cue your ears as a source of sound. Envelopment is all.....
Regards,
