So when apply to college, can he put down U.S. citizen, instead of Lawful Permanent Resident, while still waiting for the certificate?
-Yes if you are a US citizen.
I know kids may have an oath ceremony at the same time they turn in their green cards and get the certificate. I thought they become citizens until then. But I think you are correct. Appreciate your answer!
-Your child does not have a oath ceremony (not need it) because he/she is a US citizen when you become a US citizen (you took the oath to become US citizen and your child is US citizen already and thus does not need to take the oath).