I think other posters have answered most of the questions, but for point
#3 here has been my experience:
3) AI flight was delayed in BOM and they tried to pull a fast one on me at the lounge by saying I can only enter the lounge 4 hours before the revised departure time. I forced the issue at the front desk, saying that I should be admitted 4 hours before the original departure time and that the delay is out of my control. The lady called her supervisor and got the approval to let me in.
I always have to press a little harder in India to get things done!