And I'm sure he would have signed it "Your buddy Kan" too, because the letter writer's intent is clearly to avoid any ambiguity or confusion regarding their identity. Do take another look at the postscript to that letter before you build out your theory much more based on the "we" in the beginning. And let us know how many of those three colleges near you are likely to include "BTW, here's some highly experimental equipment free of charge and a link to a voyeur porn site, GLHF =)" on their official communications.
I did make a mistake on (5) in my list earlier, though - the letter mentions that the assistance payments were getting deposited into MC's account, rather than going directly towards rent, so their absence would confirm this change for the MC independently of the letter. I also assumed "subsidized apartment" meant campus housing with Kan as RA or something like that, which I suppose is not necessarily the case.