Thanks so much for reaching out to the Zoom Developer Forum and welcome to our community, I am happy to help here!
To answer your questions:
Activate (It seems to be YES)
Create a specific number of break out rooms during a webinar session (I didn’t found)
So breakout rooms are not available in webinars, but they are for meetings, you can achieve this by passing a breakout_room object in your settings field when you send a post request to create a meeting
and you can also pre-assign them manually:
Get the list of registered and attending participants (Is seems to be YES)
Dispatch a specific participant ID in a specific Break out room ID (I didn’t found)
Exit all participants of a specific break out room (I didn’t found)
You are correct, you can not send a specific participant into a specific breakout room via API, it must be done manually. And to your last question, no you can not exit all participants from a specific breakout room via API.
I hope these answers help and please let me know if you need anything else.