Its good to have inspiration from successful titles like FFXI and WoW. Copy and pasting WoW on everything isn't the best thing, but some of their features are much welcomed such as the Content Finder and it's custom interface features. Go too far like other MMO's (SW and RIFT) and people will inevitably go "Meh it is the same thing.", and head back to the game they are familiar with.

Now on the FFXI side, yes this game should derive a lot from it. Take something that was successful, make a new game that takes it's successes and make it better. That seems to be what 2.0 is anyways. Using concepts from FFXI would simply help bring familiarity to the Dev's and something they know how to work with, and more fans would be pleased than disappointed.

Also to point out. The whiners of FFXIV are extremely minimal, so no matter how good something is, the whiners will always be here. Give them a bird that craps gold, they will ask why it can't do platinum. Constructive criticism goes a long ways and whining doesn't get you too far. Yes we all like to vent out our frustration with the game, but developers can't get ideas from people just saying they don't like the system. They want you to say that you don't like it, the reason you don't like it, and what can be done to make it better. If not, your ranting is kind of useless to them.