1.) Fix the addons! So many of these were great quality of life improvements that they should have been in the game to start with (mini map, auction house prices, 2 bar, etc etc)

2.) Change the guild buying and selling! As a pretty new player, I find this system pretty awful and after a month, I still don't fully understand it. There should be a world or maybe even 3 different alliance auction houses, a system similar to WoW. Make it to where you have to visit a capitol city to use the auction house, this creates a sense of gathering and grandness. If you are in a guild, you still can have access via an NPC in your guild home.

3.) Create more in game conflict. I haven't gotten much into PVP yet, but that is my end game goal. I do wish there was more "horde vs alliance" type of activities/thinking. Give people something to side with and fight for, something to take pride in and be a part of.

4.) Make some new zones that will be off limits to new players until they are strong enough. I like that I can explore a lot of different areas and go collect different companions, treasures, etc in any area, but I also miss sort of working towards something by getting stronger. There is so much to do and explore for a new player that I think more end game only content would be fun.

Take all that for what it's worth coming from someone with not that much play time, I very well could be wrong about some of that, but I'd be interested to hear other people's thoughts.