The staff you met aren’t the people he will be interacting with. Go back and have meetings with professors in his major and the people who will be his personal contacts in student support.
As for the people locking the building, that is their job. If you go to a public library, for example, that closes at 5pm, and ask to stay in the building until your ride comes, they won’t do it either. They have families and obligations to get home to.