Will I lose the option to use my email address that was previously used?
No, but you will only be able to use that email for that account. Meaning that if you deactivate your account you will need to use that current email to re-activate it again. But if you start a new account you will need a different email address. Also, most people have never deactivated their accounts before so they probably didn't know the answer to your question, so take no offence. Cheers.
No problem. Just a warning though, sometimes PSN will still associate that email with your de-activated account. So if you make a new account, eventhough you switched email addresses with the unwanted account they still may not let you use that email to start another account. I hope that makes sense.