To begin, You were using a video that was dragged into the editing window which was not what we need. I was just trying to show how to use the innerHTML of a rectangle to load a video - nothing more. This process an important first step.
The answer to your question is a qualified “Yes”. As I have my demo set up using your example video a timeline would be accurate - as the user has to hit the “Start” button the video should have plenty of time to load from the server (not guaranteed though).
Additionally, I have it on the “Main Timeline” - not ideal. A separate timeline would be better, and a Symbol with its own timeline would be better still for this use.
However, none of these timeline based set-ups is a bullet proof method - there are other ways (via scripting) to have more precise control over events.
Having an actual Demo project that uses your intended video source (“vzaar”) will be important as there is a specific “Application Program Interface” (API) for “vzaar” as @Daniel pointed out in the vzaar documentation.
Until this is set-up in a functioning manner everything else is speculation.