Starting point - Collecting user watches, follows, subscribes, and hosts

API
5
  1. You’d only see who was in chat not whom is actually watching, As noted: [Feature request] Possibility to query actual viewers of the stream
  2. ~
  3. ~
  4. There are some details if you’d search the forums. There is only an undocumented, unofficial, unsupported end point for host information. Aside from logging into chat as the broadcaster and listening for host notifications in chat, as documented in the IRC notes on the github or this site.