The Gear oil doesn't needs to be changed at 32000 km, but you can change it as a preventive maintenance. Your Toyota Alpha will take Toyota ATF Ws.
Secondly 90% of cars go for Posish (After Market Car Seat Covers) in Pakistan. So posish walay removes all the seats in order to fit posish. I think it wont be a problem to install driver seat without triggering Airbags. My cars is also imported and comes with Airbags in seats and i removed them many times for Posish and General service without any problem.