I'm going on QM2 on Sunday and our boarding time is 3.30pm for deck 5 so definitely one of the later ones. I expect they must do it top to bottom.
In terms of the food, you'll find sample menus for Bamboo, Coriander and La Piazza (the Asian, Indian and Italian evenings you mention) in the useful links topic which is pinned near the top of the board 😊