WAN Recovery

A few questions (to start),

1. Do I use WAN IP configured for the actual interface for the "Public IP"?
2. What IP do I use if the site is using DHCP for WAN?
3. Do I need to enter a port? If So whats recommeneded?
4. Do I only do this for the HUB sites?
5. WHat if I have more than one HUB?