They have more then 4 cast members thta can be in there. It all depends on how many children are scheduled for that night. That's why at the beginning of the cruise they ask you to put down your top 3 choices and then you can request other after that. They will call you each day (if it is not your top three choices) and let you know if they can take your child. The reason for this is so they can get the "right number" of cast members to watch the kids. I do remember that one night they had about 6 cast members in there because it was a big kid night.
As for the food thing, it is only bottles, but they might be will to glet your child have cherrio's or the like (dry food) if you suply it. I know they do have crackers, but they only give that out in extreme cases I do beleive.
Also, if you put your child's pj's in the diaper bag, they will put them on your child for you. Also they have cribs and mats for the children if they fall asleep before you pick them up.
*** a little side note..... If you are on a tight diaper count, do not put "extra diapers" in the bag. (more then 1 or 2 changes depending on how long they will be there.) If you have 4 diapers in the bag, THEY WILL USE EACH AND EVERY ONE in the 2 hours your child is there. Also, make sure you have a good wipie count! I always had my travel container so I knew how much was in there.***
They really are great with the kids!
Hope this helps! We will be using the nursery this Oct for our 9mo. The kids have a blast in there!