u got to have ur own server for this. meet.jit.si doesn’t require sign up. but in ur own implementation u can add an interface to sign in and sign up.
this is also possible. jitsi has a functionality “raise hand” that allows moderator about a guest wanting to ask something. It also has something called “push to talk” where by u can ask guest to mute their mic and press spacebar when they want to talk.
2 ways, firstly u can use screenshare functionality to show entire screen / a opened application window / a chrome tab. also it has an integrated realtime editor called “etherpad” which u can also use.