When you post status there is a select button on the right bottom side which brings up a menu specifying your audience: public, friends, select person/s etc., something like that, I try and limit posts sometimes but I don't know if it works.
I once posted a comment that I though was private on an article published on another site, it was very embarrassing.... just as I posted I notice a small checkbox under the comment field saying, share on facebook, and then noticed that I was actually logged into that site with my Facebook ID.
I wanted to die.
I managed to delete the comment on my wall but it had gone onto the FB newsfeed, publicly!
There seems to be no way to delete newsfeed to limit damage in such circumstances, but I think it is possible to select your audience before you make a status update, tho not like and comments.
You can only filter your own news feed.