Federation Design Plan

Federation is a big plus in my book, I don't know much about the various protocols. The way matrix does it is less than fun for long term maintenance, I think its really important to consider long term maintenance, and balance a users control over their data and a server admins ability to keep a long running instance running well. I'd also like to throw in a users ability to transfer their account would be very nice, even if it can't move everything, being able to update friends and memberships with the new "home" server would be a very attractive to fans of federation.