I would say that I see more benefit in terms of the short term quality of life for a child using cannabis as part of their treatment than the long term. So far, most of whats discussed in the OP's video lies in the realm of "pseudoscience."
What is more of a concern to me is the legitimacy of the treatment against cancer, and how the patient doesn't have a real choice in their treatment and is unable to learn the facts. I am okay with rational adults dabbling in fringe remedies, but I'm not sure how I feel when its not the patient making those decisions.