The license is for the software only. Included support is only for bugs (with all the plugins off). If you need 1-1 support please check WordPress Help!.
Websites. A Multi-Install (Network Install) of WordPress doesn’t count for one install. Only the number of installs within that network counts. If you have 100 websites in your network install, you will need a license to cover this number.
Support. I believe developers can find the response to all their questions online. If there is a bug, I will always hunt for a way to resolve it. I might not reply to my customers without support as part of their plan. I will give my highest priority to my clients who are paying for yearly support.