Hi Chad
1=> Actually, you can control what user group your subscribers will be assigned to when their subscription expired, see
membershipprodoc.joomservices.com/joomla...subscription-expired
So in your case, yes, you can fall back to default plan when subscription expired
2=> I am sorry, I could not offer free support for migration. In good case, migration should go well. However, in case you are getting trouble, it will take much time to debug (might be because something with AEC version). I don't remember exactly the version of AEC which I written the migration for, it was from long time ago. So prepare to debug it yourself. In case you need us to check and migrate data, we might have to charge you from 100$ to 200$ for the migration (sorry, AEC database schema is very complicated and it's not easy for checking and completing the migration)
Regards,
Tuan