I'm thinking with these advise you are listing you want to share an experience with users to make the advise really teaching to readers.
Never tell people what is in your wallet, you may become a person the hackers and scammers focus on.
I don't believe this, I think there are people or person you can tell but the most important thing is not to expose your passphrase because even hackers can't have access to it if you don't disclose important feature or clue to your password. The advice therefore should be to be careful with not exposing of your password.
Well, you have to set privacy for your own account password, because that is the only way you become responsible on your own accounts. Exposing them is always a big NO as it only brings danger in the later part. And do trust yourself more than you trust others. Since in this world of uncertainties, there is no one who can trust but only yourself. Be more responsible on the things you can't afford to lose.