The answer to the sixth question has been added to the post.

Seventh question:

What is ODR? How does it work?


Please post answers in the comments (without Googling)!

Highlight for answer:

On-Demand Routing (ODR) is an enhancement to Cisco Discovery Protocol (CDP), a protocol used to discover other Cisco devices on either broadcast or non-broadcast media. ODR was added to CDP to advertise the connected IP prefix of a stub router via CDP.

Source