What's wrong with this game (in my opinion):
First, i don't hate this game. I really like it, but it gets frustrating very soon after i start to play again. I still love how everything looks and the general "main" story line.
The Game design (not graphics) itself is very interesting and (if executed correctly) would be a lot of fun. sadly this is also where ffxiv fails miserably. While on paper it sounds like a great idea to have all classes (please excuse me for using classes and jobs synonymously) on a single character (i consider myself an "advanced alter" on WoW, where i have over 20 chars and spend most of my time leveling new ones instead of the endgame) it just does not work. It could work, but it does not. And here is why:
Not enough (leveling) content. After you have done all the main story quests and all/most side quests there are almost no quests left for alt classes. It would be easier to roll a new char than to level another class on the same char.
Yes, there are FATEs, but those are extremely repetetive and get boring after a while. Then there are the (extremely wel designed!) Dungeons. They give a decent chunk of XP the first time you do them, but the overall time investment is not just worth it. This might get better with 2.1 (which honestly comes pretty late... i tought 2 months after launch was a goal for this?) but well, we will see when 2.1 actually is released. Still, there should be way more low level quests in all level ranges.
"ping"/GCD:
Due to the extremely high Global Cooldown (GDC) of 2.5 seconds everything in this game feels frustratingly slow. This cooldown might technically be needed, because the server ping is very high. There was a wrong decision being made bevore 2.0 was released to only have Servers in Japan and Canada (?). I think this was a bad decision. Please add more Servers in the US, UK and EU! Then reduce the GDC and if neccesary redesign some encounters. You also can't have encounter Designs like Titan Hardmode for example, where you have only a few milliseconds to start dodging something or you die. Not with this high of a ping. And yes, the Problem is the Servers. I can try to play the game from different locations in germany, some with Fastpath enabled, or with a VPN connection to Toronto directly. I still have (under good! conditions) a ping that is at least 10 times higher than to - for example - WoW's Servers. So either fix the ping problem and reduce the GDC or Redesign encounters to be a bit more forgiving and make the game feel faster. I don't know how to make the game feel faster though :/
Quality of Life Improvements/Papercuts:
(some might be fixed in 2.1, i am not sure...)
small things that are annoying, but can easily be fixed:
chocobo porters: Please take a look about how flight paths work in WoW. It is just too much hassle to use a chocobo porter, so i never use them. SWTOR also does this in a similar way. This should be the way to go. XIV in general uses a lot of windows with lists of text in them. That is in general a bad idea. At least i think thank it is a bad idea.
World feels too small: Please consider changing the current teleport System. Maybe allow teleporting to all major cities and one Aetheryte Destination only. The World just feels extremely small if you can just port where you want to go.
FC Access Logs: I think access logs for the FC storage/money will be in 2.1, but if not: really important!
Loot/Lockouts for alt classes: If you have me level all classes on a single char you should change Raid Lockouts to a class base, not character basis. This also would make people roll another char for each class people want to play. Also consider allowing people to help their friends in Raids, even though they have a lockout active for the current class. Dont give them loot for this, just let them help kill the boss.
Gathering Jobs: Please allow me to gather materials i need for crafting in any class i currently have active. I don't want to run around as a lumberjack if i need wood, i want to collect wood while leveling in that area anyways. Switching classes just for this is an unnecesary hassle. WoW and SWTOR do a better job at this.
Flexible Raid Sizes: Would be a nice thing to have. Yes, WoW has this, but so did XI. Please consider adding.
Note: I don't want to copy everything from WoW, but WoW does some things a lot better. Also XIV actually does "copy" a lot of things from WoW already, just -sadly- not as good as they are in WoW :P
now go and flame me for comparing all the stuff to WoW
//edit: i know this post belongs in the "feedback" section, but none of the sub forums there seemed to fit this post. There sadly is no "general feedback" sub forum. *hint hint*
//edit2: where i know how things are in SWTOR i added this to the list. This shows that more MMO Developers think that this should be the way to go.