I thought that since the survey is already over, we should add what we couldn't talk about with the survey.
First and foremost, while people should have access to faster levelling (seriously, look at the EXP curve!), there is another problem: getting one-shotted by monsters. The damage output of the higher level beasts is ridiculous if you're not playing as a Hero, who has far more HP than any of the other classes. If possible, either give the other classes a more suitable HP boost, or lower the monsters' attack power. It's kind of annoying to train when everyone can potentially one-shot you, especially if you're one of the new classes.
Second, there should be more quests, and more worthwhile quests at higher levels. The rewards for quests tend to be...Meager at best for the most part, in my opinion, unless it's a required quest for your class. Please make quests more fun and less time-consuming. No one wants to spend hours hunting for Nependeath honey or killing 1000 drum bunnies.
What else...Oh, the Inventory. It's a bit small. I noticed the Warrior starts with an extra row or two of inventory space, but other classes usually do not. It'd be nice if you could expand the rows a bit. Another option would be to simply eliminate an inventory limit altogether, and let classes stockpile as many items as memory can allow. At the very least, this would be very helpful for monster drops (like those annoying chocolates in February), and Medals (they should have their own inventory space altogether and not allow themselves to be dropped). Speaking of dropping, players should be able to "lock" their items in their inventory to prevent them f Aion dropping by accident.
Party quests should also be more numerous and rewarding. Look at WoW's dungeon system, players should be able to enter their own instanced dungeon of sorts and play without having to wait for anyone else to finish. Removing the upper level limit may also be a good idea, but adding in a higher tier version of that quest (Monster Carnival 3, anyone?) would work too.
Finally, we really need some PvP options. People enjoy a competitive element, and minigames like Omok aren't gonna cut it. If you can somehow make this happen, it'd make the community more lively, I think. Adding in rewards for participating in PvP would also help, perhaps as an alternate method to levelling.
These are my suggestions, so I'm hoping others will add their ideas too.