Linking Items to the task bar
Many potions drop and are quest (and chest) rewards for your character fairly early in the game. The reason I find myself not using them is the hassle of clicking on the sac icon while fighting, going down the list to the item i need, then selecting it. Its not that it can't be done, merely that is can't be done easily and on the fly.
I was wondering what role thrown items and medicines were to play eventually in FFXIV? I think linking potions and other items (besides the thrown weapons) to the task bar could add tactical, job related, and unique options to the game. I for one would welcome a job like chemist or a juggling job that used thrown weapons of all kinds as their main weapon. By adding various kinds of potions for higher level jobs, options to players would open up for those that may not want to level a mage job as the only good means of healing oneself later in the game. Xi seemed to gimp its medicine system by making it so you couldn't spam potions in order to stay alive. While I understand the purpose of doing this, the time restraint was so severe it made using most potions pointless.
I think the items that are in the game now like firepots could be useful with higher level versions as well. There seems to be a lot of thrown items in the game, yet no one really seems to be utilizing this. Adding skills specifically for throwing items would be a great way to increase use.