webrtc

I own a tutoring website. I need a html/webrtc based classroom which is first and foremost FAST, responsive, and scalable. It needs to have the following: Whiteboard with regular tools, ability to share screen, audio and video communication without lag, file sharing, presentation (ability to upload powerpoint/pdf while having the ability to highlight, write etc using the whiteboard tools, chat, user permissions and database ready (meaning, different users can have different write permissions etc and database from lms like moodle needs to work with it so they can login the classroom with their username etc, ability to record sessions. As examples, please see the following: [login to view URL] , [login to view URL] and my favorite [login to view URL] ( i love the design and the fading highlight tool). There are a lot of source code available and I think it shouldn't be too difficult. Also, i would like the classroom to hold webinars (where a presenter has his/her webcam and audio open, while doing ppt presentation and 100s of people in the room watching. I am sure that would require some power. Let me know if you are able to do such a thing, how long will it take, what are the challenges. In future, if you are up for it, I would like to make a ios app of this classroom which users can access and work with the browser version without problems. Thanks for you time, Reza