Gary,
JFBConnect already has great integration with Community Builder. With our social profile plugin for Community Builder, you can have the user automatically created in CB as well as have their profile automatically imported from the social network.
For Mailchimp, we don't have specific integration for that. However, there are many plugins out there that work with Mailchimp to automatically add new users to a specific list. That's really not necessary to be integrated into JFBConnect as the name/email address that comes from the registration (whether it's a Joomla, Community Builder or JFBConnect registration) is all that's really necessary.
I hope that helps explain, but if you need anything else, just let me know.
Thanks,
Alex