Two things FF14 can adopt from Guild Wars 2.

[Aellae]

Number one... Being able to retain high-level abilities even when your level is synced. Wouldn't that be great? So at lower level dungeons, your stats (str, int, vit, whatever) would be nerfed but you won't get thrown off by getting cut off with your high-level abilities.

This has been suggested for a while now and I think it would make the level experience of some, if not a lot classes much better. I can see what they tried and it looked kind of interesting at first, but with the introduction of roulettes where it is almost certain you get a low level dungeon, it is very tedious to only spam like 2 buttons. I would welcome a change.

Number two... Never experience gear decay unless you actually just DIE. In Guild Wars 2, your gear will never deteriorate unless you completely die. I think it'll make a lot of people (me included) less paranoid about forgetting to get gear repaired. I'm one of those who mostly gets his gear repaired at 98% condition.

I can see that being kind of nice, but I don't really think it is needed. Yes, repairing can get annoying, especially if you don't have crafters leveled (one day...) but it doesn't bother me enough to want a change.