Look around for the menus. Many have posted them. I did an Eastern this past August, but I don't know if the menus have changed, so I can't help you there.
However, you do not have to do rotational dining. The paid restaurants are open, and Cabanas turns into a sit down, so you can go to that without a set time.
I thought the food was good overall. Some really good, some yick, but most good. I am sure you will find something to eat, at least I hope so.
You can also order room service, and the fast food items from the ones near the pool have decent pizza and sandwiches. Ice cream is usually available most of the time, and you can bring your own cup with your choice of liquid that goes good with ice cream. Soda is also available all the time.
Have a great cruise!