if I cancel my member ship .and email
Can I reopen and and still use that email.
then I can get a QR Code Authentification
and then start all over
I'm not sure I understand your question here. If you are signed in to mSecure 5 on a device, you can easily change the account email for your account in the settings: https://support.msecure.com/support/solutions/articles/36000076322-change-account-username