1.) Changes to crafting and gathering so there is something to do at max level that isn't just grinding tomes or waiting on timers. I'm not talking about viable endgame gear, just something fun that doesn't require bleeding-edge gear with maxed out materia.

2.) Quests that amusingly go into why so many of the more common asked-for ideas are fraught with peril. I'd love a questline about a fire mage that has been rendered totally useless by fire-resistant monsters, for instance. (Also: don't add these systems, no matter how many people ask for them)

3.) The ability to replay quests or even just specific solo fight instances (3.4 end fight for example). Not for any reward, just because it's fun.