I think a great addition to the admin side of the script would be to incorporate the ability for the admin to be able to signup subdomains without having to go through the whole multi-page sign-up process at: 'myred/register.php' -- including checking email to activate, etc.... (i.e.) from the admin Control Panel.
Also, the reserved name feature only allows for a finite number of reserved words, which means that the Admin must manually go through the whole signup process for all names he/she wants to protect or reserve ...it would be great if this limitation could be upgraded so that you could enter one or two hundred reserved names, or more, for example...
joe