1) No, you cannot make a new forum account - at least not without submitting a support ticket to the GM's to explain why you need to do so. That way, they can make sure your old one gets disabled since nobody is allowed to have more than 1 forum account.
2) You can change the email address attached to your account if you need to (Profile > Account Related Settings > Type in new email address > Next to the submit button, type your current password > Click the submit button).