@kk
Opening of the compressor means you will lose the oil, seals and obviously the gas. So for the bearing change, the person may charge you atleast 6-7000 Rs.
The other problem, you mentioned about the ducts, might be with the Fuse or relay of the blower, get it checked too, since the ac compressor is putting more load over the HVAC system and thus problems with the relays/fuse is obvious.
If the car still do missing, open up the gas valve a little and the problem will be resolved.....