Consequences of changing configuration

@cahrens , @explorerleslie , @gwprice , @zhkramer , @srpearce : last big chunk, let me know what I've gotten wrong and what I've forgotten!
I read this the same way @cahrens did the first time through. I would leave the section targeted to renaming a cohort group. The item about rebalancing could go here in the "renaming" section and in the "Deleting" section below.