Great food for thought.

I think it is possible to compartmentalize- your public persona should be convincing but they don't have to expose your nyms.

I just reread your original post and basically I would discourage un-friending anyone.

Split off a persona that continues to be their friend. Big brother can continue to track that nym and assume they have a correct file for you.

Have your true development continue separately and only share what is necessary. For example: Take a new phone number but keep your old number for the people who know you by the old number. If that friend never advances then your new nyms might have to leave them behind, but you can always "visit" them with your old persona.

This can get extreme and is probably not necessary for everyone and I recommend you fully consider the psychological implications.