You definitely have to to have a good nose for sniffing out scams in the crypto world - there are thieves around every corner! I like your point system - if you follow that methodology that think you will avoid 90% of scams.
I would only add, think twice before hitting the send button in your wallet - assume that whover is asking for money is a thief until you've double checked everything about them. And avoid OneCoin like the plague, I don't know how they keep managing to trick people.
It should be less than a month old. A guy on stratis slack lost 40k in coins. That would be around $ 280,000. For a nonsense, downloaded a file with virus and gave access to his pc to the scammer.