Do you trust facebook to respect all those settings in the future, or are they likely to implement a change to the system that defaults everything open? What about selling it to advertisers and other organisations?

I'm quite comfortable with the pseudonyms of my friends. Some of them are known by pseudonyms IRL, and one or two have names that don't match their ID but are the name they use in life and at work. More women than men; pseudonymity is a useful defence against ubiquitous harrasment.