As for the auction house: If you are going to implement it, don't half-*** it. I want a web-interface to view and buy auction items while at work by logging in to my character so I don't have to be 'in' the game 100% of the time to feel like part of the game 100% of the time. This would eliminate the need for third-party websites that get information fed to them through third-party-tools (auction bots) and make a much needed feature part of your benefits, not negatives.
This should also carry over to outside communication tools like a chat and voice tool... it's like you are missing the largest element of the game, the human interaction element.
My largest problem with this game is that the entire thing feels half-assed, like an implementation of software in a company that wasn't designed with that company in mind. Don't just 'plop' features in, truly 'implement' them so that the world is an integrated unity of features that back one another up.
The UI is pretty crappy in my opinion, but a UI is a funny thing, since it's impossible to optimize it for every user, all you can do is play-test and evolve to fit needs, then make everything as customizable / script-able as possible so that each user can make it their own. To me, 'combat mechanics' and UI problems are getting intertwined here, the combat itself is terrible. I like the idea of hitting macro keys (that I can define...) to execute things from my macro bar, but I hate the idea of 'clicking' those macros or being forced to hit predefined keys for those macros. I also hate the idea of being forced to mash keys, and not have some form of auto-combat-mode. With ff11, ff12, and ff13 there are three different kinds customizable automated combat systems that we could fall back on - and while no one expects them to be amazing, having a customizable and switchable automated combat systems in place for a game like this would be priceless. There are some enemies that require little to no effort, yet we still have to kill lots and lots of them, for these situations (farming low level mobs, for example) I want to chat with my friends in text and on voice, and during this time I don't want to have to constantly mash a button to kill something that basically stands no chance of dealing a significant amount of damage to me. It would also be nice to be able to go to the bathroom without 'afk' completely killing the momentum of a group. Auto-farming-combat-bots are not what I'm talking about here, require interaction to a point, that's fine, but to have to mash buttons non stop 100% of the time we play is terrible and will eventually force people to leave the game and find something more 'user friendly' (not in ease, but in a more literal 'the human user's needs' friendly kind of way).
Posting from just above the generator.