Yes, Micromax Bharat 5 pro does have the google assistant.
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.
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.
Micromax Bharat 5 pro has ARM Mali T720 MP1 GPU which is a single core GPU and its frequency is 600 MHz.