The crossover changes are the most important IMO -- if I had your system I would listen to music without the subs and start with an 80 Hz crossover & Small setting for movies.
Next, if you haven't done so already it would be good to experiment with pulling the M100s out much further from the wall even if you know you're going to have to push them back before your wife gets home.
I find that ~30" between back of speaker and wall is about right for my M40s and M60s, I would go right out to 4+ feet when experimenting. Find the right distance with and without the port plugs, just so you know what the speakers can sound like. You might have to move them a bit closer together to compensate for them being closer to the listening position but that shouldn't be a problem with them so far from the wall.
I want to tell you to pick up some cheap (but decently heavy wire) long speaker cables and experiment with having the speakers on the short wall, but I've also been accused of sowing the seeds of marital discord by doing things like that.
Maybe just pull the speakers another inch further from the wall every day and see how far out you can get them before getting caught.
If you could pull them out another foot that would only take 12 days (an inch a day) and then you would probably be able to put a VP180 in *front* of the cabinet ans still have it aligned with the M100's
I'm constantly surprised by the variety and depth of expertise of the folks here -- I bet if you posted a current floor plan someone might think of a "short wall" layout that your wife would like, that would have room for the M100s to breathe, *and* would have room for a VP180.
