I am about to do a 4.62 to R2 migration of a site that also uses EPiServer Community version 3.1. I can think of several ways to go about this migration, but which is the best way to do it?

The EPiServer site uses SID users/groups and the community has it's own user database, with the StarSuiteAuthenticationProvider. Should I use a multiplexing providers and keep the databases separate, can they be merged, or is it better to use the EPiServerCommon providers somehow?

Say I would make a new installation of community on the migrated CMS site, is it possible to import users and content from the old community database?

Is upgrading from Community 3.1 to 3.2 a big hassle? Should I leave the community version be for now?

Many questions... All help and experiences are welcome!