The {JFBCLiveStream} tag no longer works. Facebook discontinued that widget back in October and will show the Comment box instead if you try to use the LiveStream widget. So, if you want a way for users to communicate with each other, the {JFBCComments} tag is the way to go.
As for the {JLinkedLogin} tag, what shows when you use that text? Is it the tag itself, or nothing? Can you post (or PM) a page where we can see the missing tag/button?
Thanks,
Alex