Already advertised based on initial configs due to 0.0.0.0 area 0 ospf command?
I am not sure about the task but 0.0.0.0 advertise all networks into OSPF.
You are correct. That Loopback should probably be designated passive, so as not to violate the task restriction.
Thats right, task does not make sense if all the interface are running ospf including loopback. In order to solve this task for learning do not enable ospf on loopback interface.
Thanks for the assistance once again!