Very well written OP, nice to see someone with a firm grasp on the English language once and awhile :P

I personally agree that the whole "XI is the devil" attitude that has perpetuated recently is very silly. Being that XI was the previous successful title I was very perplexed that the original XIV abandoned everything from XI. Even things so basic as ctrl+r for responding were absent from XI.

Things that should be melded from XI to XIV:
Majority of the core functionality features (/sea all, the ctrl commands (we have most of them now), etc) and the emotes. I can't stress the last one enough. I can't express how frustrating it is to not have the basic set of emotes XI had. I'd be very happy if they maintained all their current ones and just added the /grin, /huh, etc. It would even be cute to have subtle references to XI, such as an NPC making a joke about something only an XI player would understand.

Things XIV should not take from XI:
A lot of the examples you posted, honestly. All that Dynamis included followed in line with XI's story and would not fit in XIV. We could use the same concept but with different players. I love mandragoras as much as the next XI-vet, but here I also have to vote for keeping them out. They could make a "new" mandragora specifically for XIV but for the most part all of those creatures belong in Vana'diel, not Eorzea. The beast men especially, we have new beast men (I am aware Amaljaa are from XI, calm down) and they fit into the lore and such. We do have cross-world mobs though: Ahriman, Ochu, Bombs, etc but all of these are designed differently than their XI counterpart. Goblins are the only thing that never change but that is an obvious exception.

What I find very facinating about XIV is that we have been given the opportunity to really see a game in its adolescent stage. Most games are already in solid concrete by the time they hit the consumer market but we have been given the chance to see a game didn't quite know what it wanted to be and help it along.

It had very strict parents X and I who were so controlling and restrictive that XIV became a rebel and defied against everything its parents tried to teach it. After entering the real world and meeting those "cool" kids who make bad choices named W, O, and W, XIV started trying to be a little more like them. As it started actually maturing it realized that maybe some of the things X and I were beating into its skull were actually good morals, but at the same time saw the good spots of W, O, and W. Having had struggle to determine who XIV truly was, it is finally coming into its own wielding diversity from multiple scenes. I think that this kind of development although incredibly costly to the developer (SE) will in the end result in a very well rounded game. People with a wide variety of MMO backgrounds have been able to contribute feature A B or C and in the end we will be delivered a game that stays true to its roots while breaking the mold at the same time.