Yes you can make new account. But you have to wait 24 hours to make new account after deleting your old account.

Please click 'Account Info' button and visit 'Account Information' page. And click 'Delete your account' tab. Fill out the form, and click "Delete account" button.

It is impossible. Once an account is deleted, the registered information will be deleted including username, password and E-mail address. The account will no longer exist and will never be accessible again.