Would you be able to have it so the alts are migrated but all to email accounts like ([email protected]) and then have it so unless your IP is yours or no one can enter the email. Just to make the accounts more secure?
Possibly add a dashboard so you can Log In to the website so you can do various things. (E.G. Donate an account for verifacation, Change skin of account, ect...)
These could be limited by having a person get one account per day that they can change the skin and have it that they get one shared but permanent alt. But only for users. Allowing a unique system of control, but saftey of the alts.