It would be awesome, but FF is definitely not the game for it. So much of the game structure is set up to be a roadblock to party leveling. Their history of developing single player content really has its stamp on this game.

Old as it is, Everquest would actually be the best game to do this in, because questing is almost never a hard roadblock to what you can or can't do. It's also a fantastic party based game, where you do really need a party to do a lot of the content. If I had to pick one MMO where having a party was the most rewarding, it would still be EQ by a mile. It's also very forgiving of someone missing a session or two. FF, if you get off the track with one person, even by a day or two, you're pretty much screwed. The content is so rigidly locked behind and to the MSQ that it makes it almost impossible to keep that kind of scheduling up.

Great idea, and something I'd love to do, but not the game for it sadly.