I always say it's best to have just 1 admin account and if you are the forum admin use that as your account.
The admin account has full rights over all forums, including moderator rights, and more.
I've never heard of the admin account becoming corrupted, as it's simply a user in the database. The only thing that does occasionally happen is that people forget the password for the admin account, if you did that you would need to edit the database, but the following article describes how to reset the password in the database:-
http://www.webwiz.net/webwizforums/kb/admin_password_reset.aspThe main thing to make sure is that the admin account has a strong alpha numerical password and that you change it.
Moderators do have the right to edit member profiles so can remove dodgy homepages from user accounts and can also suspend, but not delete, accounts.