General recommendation to weave it all together

I just love the set of plugins you all have created and have a question about how to weave it all together. Here's the plan:
I'm wanting to create a Multisite network that offers new site registration after they have purchased that level of membership. Would this best be handled in Membership or Supporter and what's the best configuration to handle this kind of setup?

In addition, I'd ideally like to have them added to a mailchimp list when they register for this level of membership.
(bug: the mailchimp lists aren't showing up with the mailchimp sync on register)

Lastly, I'd also like to integrate appointments+ and events into a form of list management or membership management. Should I require membership to register for the events and then link those levels to a mailchimp list or again, what might be the best way to configure this kind of setup?

Thanks ahead of time for the help. My head is spinning with all the possible configurations but I'm sure there's a "best practice" to accomplish this all.