Yes, Oppo F7 does have the OTG support. You also get the dedicated MicroSD Card slot.
No. Oppo F7 does not have the LED notification light.
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. Oppo F7 does not have the NFC.
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.