In order to restore an account, you need the owners key. Not the past owners key. That's the whole point of creating a new key, so that the old one doesn't work..

A master password can be changed. You just press change password..

You are making claims that are not true. That is the same as lying.

You said this:

Once its master password is known, it can never be safely owned by another person.

That is a FALSE statement, and therefore a lie.