Traffic congestion due to construction activity at and near the international airport will set you back 30 to 45 minutes so factor that into your schedule
The airport lounge is still at temporary location. Not well equipped nor comfortable. Looks more like a gate waiting room. They should try to get rid of the mosquitos too.
Immigration are simply just rude, its a pity that they are the first Indian people you meet. Once you get past these guys, the real Indian people wait.
Make sure to arrive at the airport at least 4 hours before flight time. Have to go through countless numbers of processes and security check that would take at least 2 hours. Worst airport awards!