I suppose it's illustrative of the difficulties of such things that I slightly disagree with the author on a couple of these on where the right and wrong of things are (and that comments indicate that others would take things in yet a different direction).
Especially a lot of the "what you should have done instead" halves feel really stiff and fake as well.
Communication is hard. Not everyone interacts in the same way. (That should never be a license to be insensitive or a jerk, mind, just that it's possible to hurt other people on accident, even when you have sat down and thought about these things and are trying to be conscientious )
Also, for all of the ones with personal/romantic relationships in here, those objections really are something the person needs to say out loud, somehow. Workplace or school is one thing, and family is complicated, but you just can't expect your partner to always conscientiously be the best person they can be (and the lies you'd tell in trying to always be "polite" to your partner yourself would start to pile up and eventually cause problems). Home should be where you can feel at home. Talking it out when that does becomes a problem is essential. (I don't know what cultural normative differences I'm running against here, just it seemed like terribly childish relationship advice)