I made a registration form and modified it to use the email address and the user_login and user_email, and does some other custom actions, Don’t need to use a username in this application, it works fine. But I did try using the buddypress/bp-themes/registration/register.php.
For some reason It doesn’t seem to activate a new account, I will search through that plugin and see what it does to activate a user. If I could find out where in the database that is stored, I can just add it to the registration process.