Aha! Enlightenment moment (again). Instead of running about two-and-a- half blogs, I should roll everything into one and experiment with 'custom friends groups' until I get the behaviour I want: mundane friends and relatives don't see the not-personal stuff, Unix geeks don't see the dumb-user Mac stuff (unless they want to), only the creative-writers I'm in touch with see the SF-fan and writing stuff, and people can ask to be added if they just, like, like me?
Does that make sense?
It would have the huge virtue of not running separate user accts to achieve separation, and being able to stay logged-in consistently. But is it reliable/secure?
Regards, Ruth