Can I retrieve SWTOR account display name from character name?

There is no difference between emailing support per https://answers.ea.com/t5/Technical-Issues/Temporary-changes-to-support-options/td-p/8875833/jump-to/first-unread-message so no point creating a new account just for the sake of creating a new account

only create a new account and sub if you intend to use that account to play with moving forward