You can have your choice of meals if you like. There are buffets/casual dining available at Topsiders, buffets for breakfast and lunch or you can sit down for each and you will learn which restaurants are open and your servers can tell you. I would recommend going to each restaurant and especially Animator's Palate. The show is great and not to be missed there. You can also order room service 24 hours.
We were 3 in a category 6 and had plenty of room, not sure if you will be cramped at all with 3 boys and yourself. Others may be able to tell you better.
If you are still planning I suggest you go with the 7 Day Magic. People say constantly 3 or 4 days just isn't enough. Eastern has an extra sea day.
Ask all your questions. People on the boards love to help.