the chef mickey breakfast no biggie (we were too full to eat too much)...but since u can get 30% off with advance booking as hotel guests, you can book for one morning breakfast. best to eat at the park where there are more options/variety and ala carte menu. unless u are a big eater, a buffet is quite a waste (and quality was not to my expectations).
we didn't do any character breakfast as the characters will have appearance at our hotel lobby (check their timing) and at the park - though need to Q up 15-30 min just to take a pic with them. we managed to take pics with goofy and pluto. chip and dale, mickey and minnie are very popular characters.
if you intend to spend some time at citygate mall, you can have your lunch/dinner at the food court there. also, the mall has a big supermarket so you can buy some stuff there (e..g extra diapers, fruits, bread, etc) if you need....