Also, it is difficult to pinpoint elements that are typical Final Fantasy.
I disagree. There are some pretty basic elements that have made it into "canon" that are easily identifiable. Though they may not be in every single installment, IMO the vast majority of fans polled on the issue would identify the following as FF staples:
Chocobos
Cid
Airships
Moogles
Biggs and Wedge (to a lesser extent)
Crystals
Nobuo Uematsu
The "Prelude" music theme
Fighter, Thief, White/Red/Black Mages (and Blue, to a lesser extent)
Holy, Ultima, and Meteor spells
Summons (by whatever name they go by in each specific game)
Bahamut
A plot involving the takeover or destruction of the world, and a group of resistance fighters trying to stop it.
Wrap all that up with some box art designed by Yoshitaka Amano and you have just about all the prerequisites of a FF game. I thinks its a pretty well established formula at this point.