Seating surfaces are the only parts that are leather, maybe the insert in the seatbacks too. The back of the seat and rear seats are indeed vinyl, as are the door inserts. That is part of the "premium" interior. I have 79,000 miles on my car and you should see some of the wear on my drivers marks seat. It doesn't look horrible but it definitely looks well used.
My drivers door has the same "flaking", although I think it is more likely from something rubbing against the plastic when entering and exiting the car. My passenger door doesn't have that marking.
Well, I discovered the cause of the flaking, it's the seat belt being released. I'm short, so when I adjust my seat, it's way in front of that area I showed you by a good 10" or so. When the belt releases it whacks the door with the hard part of the connector. Not much I can do about that.
I still prefer leather. I love the smell of it, the way it wears and how even on the hottest days, it does not get as hot as vinyl. You don't stick to it either :P