Look into facebook groups. A bit of a pain to setup (especially compared to circles) - but it gives you quick ways to limit the news-feed to only a subset of friends or to limit who can see you online.
Sure, but that's extra work, and the people I'd allow to see my presence generally can reach me in other ways.
Then don't use it! Seriously, you said the problem was that you didn't want anyone contacting you. But the fact is that FB does this quite well, and it's not that much work. And, it's damn convenient. I, awhile ago, basically switched over to it completely, as it integrates into my Jabber client quite nicely. Now people know if they want to contact me, they should use FB IM.
I assume you mean FB lists, as the groups feature is quite different. /pedantic