I cannot believe in this day and age people don't understand the dangers of passive smoking. But again smoking is legal so people can stand atop of their hill and look down at those horrible people taking illegal drugs, even if some are arguably safer and actually have health benefits
Please don't come with things like facts from scientists and doctors. It's illegal and therefore cannot have any positives. However cigarettes and alcohol are legal so people will defend them all day long
But the table does not show the amount of people harmed as that would be no comparison, rather it shows percentage chance of harm happening based on stats iirc so the amount of users is somewhat irrelevant
Never done them myself, however I would suggest that as with most things its all about setting. In the middle of the beautiful countryside with friends and no busy roads would probably eradicate most of the problems you raise, and there must be ways to level out the nausea?