Yes, Micromax Bharat 5 does have the OTG support.
No. Micromax Bharat 5 does not have the NFC support.
We have not come across any user's complaint about it so far. Since the model is new, you can expect that such issues reported by users only after a certain usage or time.
Yes, Micromax Bharat 5 pro has dedicated LED flash for the front camera.
Micromax Bharat 5 pro has ARM Mali T720 MP1 GPU which is a single core GPU and its frequency is 600 MHz.