Pretty useful information for me. I was doing every single of the mentioned mistakes. Your efforts are much appreciated.
This article have missed to cover about low fee newbies used to put to save cost on payments leading unconfirmed transaction for many hours. That will make them panic about bitcoin and they will start blaming bitcoin network for it and some may even opt out from the idea of using bitcoin again.

Only the article was missing the commin mistake newbies make, by setting low fee in transactions then gettting unconfirmed transactions and blaming the evil nature of bitcoin as stated by SONG GEET