Annual registration atuomatic Deadline

I am managing a sport club web site.
Each athlete has a medical statement that expires within the year.

First, can I manage this field (expiration date) at admin level, not allowing the user to alter it?

Second, am I allowed to have CB sending an automatic email X days before expiration warning the athlete that his certification has to be renewed.

Third. Can CB prevent the user to login after that deadline unless I (admin) renovate his annual dedadline?

Thanks

I'm interested in a similar function: giving users a deadline. When the deadline has passed, they can still log in, but I don't want them to change any data.

Have you found any solutions to your three questions?