Glen, we have plans for implementing this feature in the upcoming update. For now I cannot tell you that it will be 100% available in the next update, but we will do our best to add the Friends only and Show by username modes as soon as possible.
I have a problem near to this topic. My complete website and plugins are uptodate. But this plugin makes every new picture password protected. You can open and view pictures but you can`t rate because "Rating is unavailable for password protected photos".
We are aware of this problem and it has already been fixed. You will receive the fix with the plugin update. The update is scheduled for the next week.