It's not that I can't "see" what you're suggesting. I can picture the whole thing. The problem in taking it any further than that, for me, is that it is a story about a person that is not in the case, not in the video, not in any evidence that has been released, not... anywhere. And this imaginary person has extremely serious, clinical psychological problems, has a gun, is aggressive upon slight provocation, is so deluded as to run after Elisa Lam in response to perceived threat, gives specific timed instructions to her, has elaborate conversations with her, and then kills her or, fatally, "detains" her. So far, getting away with it.
I'm creative, too. I can make up just as complicated a tale with a completely different made-up character as long as I don't need any more evidence, back-up, or logical reasoning than your story does.
Do you not see that?