If your page is set to private ie friends only then no-one else can read anything there, even if your friends post to it and have their settings more public.
There post/comment will be viewable on their activity, showing they posted to your wall, but anyone going to your wall cannot read more there
But
allowing Friends of friends is not private and allowing Everyone makes it totally public

Be sure to reset your privacy settings as the new changes reverted some things that were previously set private to public