144 Hour Visa,YYZ/PVG and PVG/HKG/KUL (seprate itinerary)

Your itinerary is definitely eligible for 144 hour visa free transit and you do not need any kind of visa. It is important to emphasize that it is perfectly fine to travel on separate tickets and on unrelated airlines. The only detail that matters in your case is the segment:

Toronto - Shanghai - Hong Kong

Everything before and after that is irrelevant.

Just to mention one important detail. Within your itinerary:

Toronto - Shanghai

and

Shanghai - Hong Kong

You are not allowed to have any additional landing within mainland China of any kind. While in Shanghai you are allowed to visit wide area around Shanghai, Jiangsu and Zhejiang provinces included.

In the end I encourage you to use correct terminology because it is not 144 hour visa, but 144 hour visa free transit, so there is no visa of any kind at all. Have a nice journey.