Dual problem

When XFINITY installed my gateway they hard wired the gateway to a separate dual band router that carries a different name and password from the gateway. They also installed extenders that are dedicated to TV and one computer. The engineers were explicit in telling me not to use the gateway. 

I downloaded XFi a few days ago and was really confused by the message. Am I supposed to change the names and passwords of my router? do I need to do something about the extenders? The engineers were here for over 2 days doing this so I am certain that I cant.

Second, because I still have continuing coverage issues in my house (i see all of my neighbors signals all of which are stronger than mine) I bought the XFi pods. The instructions were clear that I have to first connect to the gateway which I did then plug the remaining pods around the house. However not one of the pods is 'located' I have tried six times. I know I am not a technical genous but... advice?

Are the issues above interconnected