I was hoping someone would tell me their opinion on the right way to go about this.
I run several minecraft servers and I am looking to consolidate our upcoming websites to share certain things but also have separate things.

Shared: Members and their statistics such as post counts
Separate: Home Portal, Forums (without violating any tos xenforo has)

So basically you have one database for the user registration, once they register on one forum they would be registered on all of them. If you have any tips on the best way to go about this or some ideas of your own, do share. :) Thanks.