Yes, Micromax Bharat 5 pro does have the google assistant.
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.
No. Micromax Bharat 5 does not have the NFC support.
No. Micromax Bharat 5 does not have the fast charging support. However, you can use chargers up to 2A output capacity and reduce the charging time.