Shouldn't an admin password for stuff like NATS etc. work likes this?
 

1) Admin goes www.adultprogram.com/nats/sendmepassword.php
2) sendmepassword.php sends a random generated password to [email protected]
3) Admin goes www.adultprogram.com/nats/login.php using this random password to login

Then only the owner of [email protected] can log in

no. It should work just how it is. Your method wouldn't help at all if email got compromised which is how most passwords get discovered (via forgot password forms, etc). It would also be very inconvenient.