Your plug-in works well. I've been using it off and on for a while, and through your development, it has improved significantly.
With all the features you have as a part of this plug-in, I would like to see an additional "module" where one can require specific information as a part of the new user registration. I would like to mandate that a First and Last Name be filled out.
It would even be cooler, if those names were checked against some form of names list, before being approved. If the name doesn't match with the list, send it to the administrator for approval.
This could be done as a part of a different plug-in, but I would like to see it integrated with the features of your plug-in.