No. Oppo F7 does not have the dual camera set up. The front camera is of 25MP and the rear camera is of 16MP.
No. You cannot record 4K videos with the Oppo F7. Maximum resolution of video recording is full HD.
No. Oppo F7 does not have the fast charging support.
Yes, Oppo F7 does have the Corning Gorilla Glass 5 display protection.
The Oppo F7 is a good upgrade over the F5 in terms of battery life and SoC performance. The selfie camera is also easily one of the best in this phone's price range, and new additions like the Sense HDR mode and AI Beauty work well most of the time.