I have taken last Dec to Phuket (nite flight) with my girl and hubbi. Based on my previous experience:-
1. Fligth delay? No wor...on schedule and quite good!
2. Catering on flight? No...but you can buy food and drink @ airport or book the flight meal when u make the rseservation or @ flight. The food is quite nice and not expensive!
3. If book via online, u need to pay for the luggages and only hand carry of under 7KG is free. Just check the website of airasia can help!