Pitfalls when using twitch or youtube as a platform for webinars with integration to your service?

Question

YouTube

Task:
There is a service where users register.
One of the sections of the service is dedicated to webinars. Some webinars must support up to 1,000 participants and up to 10 speakers. It is necessary that once registered, the user from his personal account has access to webinars and he does not need to separately register on an external webinar platform It
is not profitable to write your own webinar platform, so we want to limit ourselves to writing a system that distributes access rights, and use ready-made solutions for the stream itself . Therefore, we consider 2 options:
1) Use a ready-made paid solution, which can be integrated to itself through api. For example, https://livestream.com
2) Use twitch or youtube.
What, in the case of twitch or youtube, will there be pitfalls?
Is it possible to make a broadcast on twitch or youtube private, use their api to insert it on your site and distribute access rights there?
Is it possible to connect about 10 speakers to such a stream?

Answer 1

When youtube is integrated into the site, the ability to view comments disappears. I saw the following implementation of a chat on webinars - integrate a VK wall into the site and use it as a chat
. Several speakers can be connected via hangout or skype (if you need a desktop demonstration).