Well, I tried cramming the 7Pro into the PF115 with the lid off, and sure enough, even without feet, that tweeter magnet is gonna hit. It's less than a 1/4" off, though. I do think that inverting the baffle might work, but then you'd have the tweeter on the bottom, which I don't think would be ideal. If you don't have an absolute requirement to be able to use that fliptop lid to mount your head, I still say that the 7Pro with one or two PF115's is a slammin' rig!
Regarding the PF115 vs PF210, I can't add much more to what's already been said, but the primary impression I received after playing them at NAMM was that the 115 had a bit more going on the midrange, and it seemed more willing to "growl." Of course, all of the cabs at Winter NAMM were the ported prototypes - except for that one sealed PF115. I'm quite fond of the PF115, even with other heads.