I personally don't like it not knowing where the food comes from. The centre my child goes to have their own in house cook and i do see the principal going to fish market every weekend to get fresh fish for the children in the school.
If it's for events/outings (we had a parent-child outing to The Polliwogs), I'd say it's okay. But if it's for day-to-day meals at childcare, then I'd prefer not to!
Yes its common. You can ask for the food caterer source. And whats the menu, They should have a menu
Yes it's normal. some CC do not have their in-house cooks. So they would cater food for the kids.
I wouldn't like my child to be in a center which caters food.