while I think I agree with you, your arguement seems to be convoluted and sporadic. There are plenty of elements taken from previous games, but that's nothing new. As summons go, only two are origional, while the others are staple summons that appear in more than just one other game.
The gambit system doesn't exist in any sence what so ever. It is the most origional combat system, which is a point of annoyment for me, as I would have loved some sort of gambits to make sure I have some sort of control of my party members (such as always heal me first, because by the time you're done healing the other party member, I'll be dead, start over again)
You overlooked the whole hunt system that was relived from 12 as well, even though it was poorly implemented.
Lightning (not her sirname, it was hinted and outspoken quite often that it's her first name, which she changed after Serah became a L'cie) was origionally meant to be a female version of cloud, that was one of the main points given to the design team.
Alexander always looked ike a castle, he was some holy knight, but he always looked like stone wall with a face.
I failed to grasp how your point about Vanille even related to any previous games, which I thought was the point of your arguement.
To end, I agree with you, it does bare many similarities to previous games, but it's hardly the first to do it, and neither is it a bad game, and does have origional aspects, just not as many as I would have wanted.
Also, you need to work on making an arguement, it was horrible to read and took me about 4 times to grasp what you were trying to say on certain points.