Mike, exellent ?'s , I can't help yo with all of them but I can help with a couple things
As there are a very limited # of tweeters available, it's not really worth doing an MTM design with them. Now, there may be guys who have a set of Neo's or a speaker that is already using them which they might be willing to pull them out of , in that case, cutting the top MZTM section off may be an option..... I actually have a few extra baffles that we had some minor issues with. they won't get used for full Otticas but they could be made into MTM's easily enough. Problem with that is after cutting the MTM section off, you have very little (.25") below the lower NQ, we'd almost have to cut you a new pair of baffles with more room below that woofer. Even with those, you'd have to get a network from Danny as youi'd be needing a 2 way network, something youi'd have to discuss with Danny.
We are planning to do some X-Otticas at some point if anyone expresses interest. It is a bit more than just removing the waveguide and chaning the tweeter cutout. The MTM section needs to be tightened up by an inch keeping it as tight as possible for the higher c/o point , you can gain that by removing the waveguide and switching to the Peerless cutout/recess. This in turn shortens the cabinet by an inch as well so the wings have to be shortened and the notch for the open Neo 3 needs to be removed. With regards to an MTM, the same appies as I noted above....cutting the top section off will "work" but you really need to just cut a new baffle or you end up with very litle material below the lower NQ.
My room is only about 12' wide but it is 18' deep. I'm lucky as the room actually sounds very good. I have everything on the short wall which leaves my subs up against the side walls and my mains a bit closer together than I'd like but it is what I have to work with. I'm still trying to figure out how to make triples fit, I just love the added weight especailly at lower levels which I listen to a lot.
jay