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.
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.
Yes, Micromax Bharat 5 does have the OTG support.
No. Micromax Bharat 5 has a mono speaker.
Yes, Micromax Bharat 5 pro has dedicated LED flash for the front camera.