Well, to combine registration with contact form and email list, you could have a registration form with a custom field for subject and another for message, set passwords to be generated by WP, customize the New User email, use the List Server integrations with a list server for the mailings, or the registration notification to integrate with another service.
WP Admin -> s2Member -> General Options -> Registration/Profile -> Custom Field
WP Admin -> s2Member -> General Options -> Registration/Profile -> Allow Custom Passwords
WP Admin -> s2Member -> General Options -> Email -> New User
WP Admin -> s2Member -> API / List Server
WP Admin -> s2Member -> API / Notifications -> RegistrationIf you want the registration form to be in a page other than the default registration, with s2Member Pro you get the free registration pro-form, which you can use in any WP page/post.
I hope it helps.