Online Presentation App - Help

Hi everybody.

I am new to AS3 and i have to do something that requires AS3.
i don’t want you to give me source courses. just, i need to know where to start.

Therefore , i wanna develop a online presentation app with video camera instance. i hired a server for dealing with the web cam issue. That is done.
There is also presentation graphics area in the app and a user list area.
This app divided in to 2 files, one of them is used by the presenter , the other one is used by participants. of course, user list shows the users who are connected to the system.

To illustrate, if presenter changes the graphics, it must change for all the participants monitor. And if the presenter allows a participant to open his/her web cam, that permission must reach that participant immediately.

For simplicity, this app must listen to server to obtain the changes.

Ok, i have developed something with AS3 and PHP / MySql. In AS3, i have a timer, and it loops for 3 seconds.
However there is lower performance than i have expected.

Now, it is time to questions :

  1. do i have to use socket programming ?
  2. if yes, do i have to hire a socket server or not? can simple PHP hosts deal with socket?
  3. if no, is the way i followed right or not?
  4. what is your advices, what is the best way to overcome this task.

Already now thanks, i hope someone helps me to figure it out…