I think we're probably straying into the realm of more detailed legal advice, as much as you have tried to structure it as a technical question.
What I can say is that throughout the history of the jurisprudence on the criminal law, the Supreme Court has been quite clear that it's a power that needs to be circumscribed in order that it not spill over and start to take up too much of an area of provincial jurisdiction. You therefore have examples of such cases as the reference on the Assisted Human Reproduction Act, which struck out several provisions from that legislation because they were overly concerned with matters to do with regulation of a profession and a business in a province.