Note that clicking on bottom of page popup notification to view new content does not mark the actual notification as read - so have to go back to that to do so.  Is it something I am doing?  Or just poor programing?  

it has been like that since the purple makeover.

Along with marking all read if you click on one of many?  Have got used to that and click on oldest first to try and keep track.  

Why not have the option to delete a notification once it has been read? And the same in all your past posts and reads. Maybe that would speed the site up.