People getting kicked out of conference

Users are getting kicked out of the conference and in the room we see user"has been kicked out of the room by . Reason:".  Why is this occurring?

Also is there a way to turn off the notification of a new entry in a conference room so that the spark icon does not blink when other enter a comment, but instead reviewed when you can have a chance?

Also, is there a way to view the history of a conference before you join?

We are a helpdesk and want to use it to ask questions, see if others are experiencing similar issues, education, etc, but it would be most helpful if the information could be ongoing, if you will.