I don't have a castmate to offer you but darnit Samwise. I need to try and lure you into my games (since they both kind of meet your preferences).

synodiporia has changing settings with a slant towards high/urban fantasy ones. It's on the larger side and has variable speeds - three weeks that are fairly fast and then five weeks that slow down some as the new setting-rush slows down. It has the option for short-term AUing your character each setting, but that's not required. Sam would be able to learn supernatural abilities here.

lasteden is tiny and at first glance space based, but it's really more high fantasy that happens to take place on the inside of a Moon - and the Spring faction would be a perfect place for Sam, it's essentially the Shire with some nature spirits in it, very farming oriented with a chill mentality.

Both games are fairly plot-oriented, but Syn has the advantage that you can (mostly) restart every two months if you go completely lost.