re: 1. Your context is still wrong. There should not be any reference to a CN, just to the OU that your users are in.
Sorry the point that CN shouldn't be in context is just plain wrong. Here is mine and it works fine
CN=NAME REMOVED ,OU=Generic Email,OU=Generic Users,OU=NAME REMOVED,DC=XXXXXX,DC=XXX,DC=uk
I've taken a couple of identifiable bits out but that is what it looks like and it works fine.
Things you need to do as Ken says map the fields from LDAP to moodle
Run the script to bring over existing users at least once. If you run this on the server from a command line it. From the set up it looks as though you are trying to give existing users access to moodle so you have to do this. The script is \auth\ldap\cli\sync_users.php
That will also give you some output on the process and might help identify what is going wrong.