how many users can be in the room and watch at most? I need 30, can I?
The webcam system is limited to 10 online users / room. If you you just want to watch and chat 30 or more users are no problem. Does that help?
can I increase the volume?
You mean increasing the number of webcam users?
Yes, you’re right. How to make it possible for more than ten people to watch a movie
As I said if it’s just about watching and chatting you can go way beyond 10 users. Only if you want to have the webcams enabled or use screen sharing the limit is 10 users.