Thanks for identifying all those methods of fraud. It is useful for all to see just how many ways people with bad intent can cheat the system.
I guess it is a matter of degree… and it is gray. And it is buyer beware. It always has been. Some buyers will choose not to pay for impressions that are not visible, forced upon users, etc. even if those are not “technically” fraud, according to your definition because they didn’t involve bots.