Not sure I can think of 5 college players better than him. I think Leonard Williams and Amari Cooper as a probable bet, but after that you have Winston, Gregory, and Shane Ray. I don't think he falls lower than the 3-5 range and still think he is a likely top-3 pick.
I agree he would not be able to step into a conventional pocket passer role year one, but I wouldn't Chip Kelly building an offense especially for his talents.
Looking at the draft order, here's my take:
1: Tampa needs a QB and the scuttlebutt is they're going to take Winston.
2-5: The only team that might be in the market for a QB would be Washington but they have a lot invested in RGIII to give up on him just yet.
6: Jets could be in the market for one.
7: Bears, maybe, maybe not. QBOTF could be but not in the first round. They're basically in the same boat as we are.
8-9: No.
10: Rams, maybe.
So, the Eagles might only have to get up to 10 so a trade might be logical especially if Mariota keeps falling.