I don't think getting SP to stay at a certain spot while logged off is such a good idea. However, if SE could make some sort of out-of-game mini-game that we can log in to play on Lodestone or something where we could gain SP I'd be all for it. Assassin's Creed Brotherhood had something similar for Facebook and I personally quite enjoyed being able to level my Assassins and gain more florins while out of game. While I'm wishing upon a star, I'd also like to be able to manage my inventory and bazaars out of game as well as chatting with friends and LS mates in game through a browser.