" I changed the network setting files" This is where you broke it. You can't change the network setting on the box. It has to be done through the NDLP GUI.
Restore the VM and try again.
I don't think so because I changed 3 network setting files directly on the box.
I don't know if you have another network setting that I don't know but, yes you can change every config with the CLI. It's a linux core.