There is a lot of hand-wringing about the exact definition that I think is mostly unnecessary. Yes, there are a fair few edge cases, but most of 'fake news' is pretty easy to spot. Examples include the Pizzagate nonsense, the Bowling Green crazyness, anti-vaccine insanity, Race-war baiting, Holocaust denial, etc. Those last two probably make up the lion's share of easy to spot gibberish, but I'm not counting. Likely 90% of 'fake news' is that simple to catch, even to those who are medically mentally handicapped. It's the last 10% that all the worrying is about, as well we should. But don't think that the large majority of 'fake news' has any credence whatsoever.
It seems your definition of "fake news" is conspiracy theory. While I agree with you that most if not everything you listed is likely nonsense, it doesn't make them "fake news". There are fake news stories often surrounding these narratives, but the conspiracy theories themselves are not "fake news", as they are not news to begin with.
True, I do think that the endless stream of these conspiracy theories on scummy ad-bait websites, day in and out, is 'fake news'. Just like the chum boxes on the bottom of crummy articles peddling 'doctors' hate him' and the like are also fake news. To me, it is a broad umbrella. Trying to winnow down 'fake news' to: not conspiracy wackos, not ad-bait, not debates on he-said-she-tweeted, etc. is all not productive. To me, they are all 'fake news'. Still, as I said, I think ~90% of 'fake news' is incredibly obvious, and as these things are part of my definition, I think you can see why I believe it is so easy to spot.
