Hi, I just checked and the demos on the position parameter page are working as intended and interactive.
You press the play button and drag the playhead (red triangle).
Is there a particular browser that you are using that has errors?
Sorry if you thought you could just drop your own code in there and have a visualization of your timeline built for you. That's not how they work. They were built just to accommodate a very narrow set of super basic use cases. However, these basic use cases can be combined and tweaked to make extremely precise and intricate sequences. Once you master these basics there should really be no limit on what you can do.
I'm not really sure what your question or issue is. The best thing to do is to isolate the problem as best as possible, which begins with removing everything that isn't related to the problem. Unfortunately, none of us really have the time to read through hundreds of lines of code and try to figure out what might be wrong.
90% of the time just going through the steps of reducing the code reveals the problem.