First of all, awesome plugin!
I use the confirmation mail feature for preventing email abuse (great feature!). It would be great if registered users didn't need to get the confirmation mail (they already confirmed their email when registering their users). My suggestion on how to implement this is to have a checkbox below the "Enable confirmation" option, like "Let registered users bypass confirmation".
Thanks again for the great plugin! (next beer is on me, just donated to you) :)