Re outside interest in and the dauntingness of the RPG community:
Speaking for myself, I have never even seen a game of D&D played, much less ever played it myself, so that's one avenue that I have no idea how to start walking down. Tevish once, long ago, showed a character sheet with all the non-essential/non-tweakable stats and boxes blacked out and I remember still being kind of lost. Freeform RPs are more a matter of subject matter for me, as I only really have a mental background for M:tG and therefore either don't know how to operate in a D&D style of world or simply don't have the interest in such a place. Mafia is another issue altogether, since I have a) had no experience in either mafia types of games or even deception types of games (I have played very few multiplayer anything, video, board, or otherwise), and b) I am rather put-off by the idea that most of the game is not actually done "on the board" as it were. The only forum games I've been able to play through completion have essentially run themselves by having absolutely everything happen on the "game board" which players posted at the end of their posts.
On that note, there is an entirely separate issue of trepidation on my part due to the games I have or have tried to be a part of. Tevish already noted the Coalition Wargame, which I would like to note did get reincarnated on these forums but died due to reasons I can't fully wrap my head around but which I'm positive had to do with negligent GMs. A freeform RP that I tried to get into on the Map of the Planes group back on the mothership died after a few posts because of the GM disappearing. Yxoque tried to start an hybrid RP of some kind that was going to use stats but in an undefined way, but they never followed through and I still have a character sheet stashed away for a game that never got out of the concept stage. As I already said, the only forum games I've ever been a part of -- the "flavorful voting games" that were once run by Skibo_the_First on the mothership, plus one which Yanmato and I successfully ran -- were designed to run smoothly without a GM as long as players kept up with their moves and posted an updated game board as it were (that is, the life points of the factions). The point I am trying to make is that I don't really trust anything that is supposed to need a singular person to act as an overseer for when or how things happen.
Re using M:EM material as RPG settings:
I think most M:EMbers wouldn't object to seeing our settings being used, although the same issues arise as when dealing with an RPG set on a canon plane -- namely, things like keeping the planeswalkers from a single plane as close to 0 as possible, not destroying the plane(s), not using natives in races other than those found on the plane in question, and not creating new races for fits and giggles (although we're obviously more flexible than canon in that regard).
Logistically speaking, I can't personally see it being too much work on our part if people want to set up RPGs on our worlds. All our accepted works are easily found in our Archive (which I try to stay on top of), and now even moreso due to the Index thread; and most of our planes and characters also have wiki pages for people wanting to read up about them. Of course, I don't know what kind of input you all might need from us in this endeavor. As Rubik has noted, something like this has already been attempted and, from my recollection, not much was needed from our end, although I don't actually know what became of that. I believe it died at some point from inactivity.
I'd like to make a final note that, for a long time now, I've wanted to make another flavorful voting game like I mentioned earlier, and in fact have the vague outlines for one set on Mercadia, but I've not been able to complete it and want to read the novel Mercadian Masques before really committing to a plane I have almost no real knowledge of. I mention this because, being the stickler for rules that I am, I never had any intention of posting it anywhere than the PBP area here.