An afk timer would do a lot of good as currently a lot of people stay online just so they don't have difficulty logging in. This prevents a lot of other people being able to enjoy the game.
Most importantly, however, is the queue system. We need a working one. Otherwise we are left to sit in frustration spamming log in and getting all kinds of errors.
World transfers would also work, although I'm not sure how well. A lot of people have already grown attached to worlds/FC's etc.
For example, I'm on Ragnarok and I became attached to Ragnarok as it is Europe's only Legacy server.