Jocelyn,
It is vital to have clear expectations, course schedules, assignment due dates, etc. Video can provide a higher level of interaction, but it still requires the student to interact. I use synchronous tools regularly; however, just like a regular classroom you get the lurkers just listening to the conversation, you still have to encourage them to join in. I hear the argument of lack of immediacy fairly often. Do students in a traditional class live in your home and get 24/7 response from you, of course not, they might get your immediately attention for an hour and 15 minutes… >>>