Gogarty writes:
A cop told me once never to give your keys to anyone else, including your
landlord. If he really has to get in then doors are cheap.

The cop who told you that is a moron.

Most states prohibit tenants from preventing the landlord
from reasonable access to the property. Most boilerplate
leases have similar language in them. Therefore, changing
the locks and refusing to give keys to the landlord would in
most cases violate both state law and the lease.

And the door is only cheap until the cost of replacing it
comes out of your damage deposit.