Just to comment on the likenesses of SW and LoTR in connections to FF12, I will first say of course!
Since when hasn't the best of the out of reality, futuristic or medievil style of storylines not featured a small group of heros on a quest to defeat an evil Villan/Empire or what not with countries quibbles going on in the background? As far as I see its a common appearance.

Second, something as large as conceiving the idea for a whole world is going to need inspiration from somewhere and where better to get ideas from something that all of the staff can understand than a few viewings of Movies that fit the bill. Ghost in the Shell inspired the Matrix for instance so why not this? Other FF's have been inspired by a mix of Technological and Magical Medievilness so it's arguable that the editing and storyboarding took a page from Star Wars then had Squeenix's airships put in.

Basically put unless Vaan and Ashe start marching off to Ye olde mount Doom to defeat Darth Vader by dropping some random piece of jewelry into it's depths you can't convince me that the storyline itself was tainted by other referances, it follows the basic Fantasy Storyline tradition and I don't argue, I like that.