{Curiosity} Where did the original concepts end and new begin?

[Magis]

I wonder, was the Crystal Tower ever a part of early lore? Some of the developer comments suggests that at least that Dalamud and Bahamut was planned for a different context in 1.0 than how they were ultimately used.

I'm also wondering how much of the Ishgard/Dravania conflict is from original design plans and how much was created after they made A Realm Reborn. Same with Midgardsormr's role in the story.

Well, Tanaka designed Final Fantasy III so it may have been his idea to put it into FFXIV. Also during FanFest, we learned that the whole Dalamud and Bahamut thing was Yoshi's idea.