These criteria are the criteria that should be used when considering domesticating a wild animal not really criteria to be classified as domesticated. For all of the reasons you list I would say that domestication of BP could be possible.
I disagree with your first point. Ball pythons primary food source is wild rodents and they do not suffer by eating them solely. I don't see any evidence that selective breeding has helped to change their diet in any way. Conditioning on a case by case basis certainly has been done and does help in many cases. Although I disagree with the assertion that BP have a flexible diet I would say that modern shipping and globalization has made a flexible diet much less necessary for domestication.
I also agree that recognizing a social hierarchy is not quite as important as the rest of the criteria.