Yes. There is a way to set your asylum, to friends only AND have public posts.
The friendslock command only effects the initial post - members and yourself can edit the security level.
Uh, which is why I have to check one of my flocked communities for public posts.
There is no way to stop the editing to public.
Personally while I like having automation for the age checking for restricted comms, I'm not so sure about the flocking, since LJ's system fails somewhat in that regard.
The other thing that is fucked up with LJ's flagging system is the removal of LJ-cuts - it means that warnings are unable to be seen outside of the post which makes it harder for people to know what the post is about...
I think with LJ's current setting there is a way to do a pinned / note thing that will stay up despite flagging. It's only with some layouts and comes under the custimsation options.