Can I make Voice/Video Call in Desktop or Web App with Cisco Webex SDK?

I need to make a (desktop or wab) application that can make voice / video calls based on Cisco Webwx SDK. And I had a few questions. I would be very grateful if someone could answer them.

1. Can we control the video / audio stream of different participants flexibly? For example, to broadcast different sets of video / audio of other participants according to their roles or groups.
2. Is it possible to use a participant’s video / audio stream in parallel? What I mean is to connect them not only to the conference, but also additionally broadcast members to another user who doesn't take part in the conference and / or another service.
3. Is it possible to write personal messages to the participants (users and guests) during the conference?
4. What are the minimum network requirements for the normal operation of a videoconference? Is there any optimization ways for the "weak" (unstable) channel?
5. Can we add custom parameters to the generated links?
6. Can we create custom software based on the Cisco Webex SDK (with a unique graphical interface)?
7. If not, can you suggest other products for solving such problems?