User registration with e-mail notifications to user AND administrator

I have this scenario:

1. User registers with additional fields (meanful for the role he gets later in registration process)
2. Admin and user receives notifying E-Mail on registration
3. Admin sets user active and gives him a special role
4. User gets an e-mail notifying that he is now approved for the site.

Any ideas to realize the scenario above?

My solutions are all incomplete:

1. Using profile module to add additional fields to the registration form
2. The admin gets the same notify message as the user by using an additional user_mail () command as adviced here:
http://lists.drupal.org/archives/support/2005-07/msg00082.html
3. The admin changes the status of the user
4. Admin must write to user with his e-mail-client, because an automated e-mail to user by approval is still not offered, allthough it is a very old feature request by the community, e. g.:
http://drupal.org/node/1828
http://drupal.org/node/5671

Another disadvantage: The additional fields by profile module are only needed once and should not be seen by user again, but now they are part of his profile

So I prefer my second solution, but also incomplete:

1. Using webform module for registration and add all fields needed for that in one form.
2. Should need then a cc:field option for admin adress, so both, user and administrator gets this mail, as wished here by someone else here:
http://drupal.org/node/20263
3. Based on informations of the webform admin adds a new user with role settings etc. ( administer > users > configure > User registration settings is set to: Only site administrators can create new user accounts.)
4. Because admin adds a new user, no welcome message will be sent to this new user. How could I change this and notify the new user by e-mail? (Haven't found any hint in the forum for that)

Thanks for any help.