Scamming
Scamming, this in particular is a crime in any nation, so what I understand here is that scamming is a punishable offence in the forum, and a situation the forum notice that your motive to be here is a scam, the account of the user will be damage with red trust. Scam should be avoided because it's one of the things forum forbids, and also be aware of scam.
All of your points are excellent, but I had to pick a few to discuss. You can see that the majority of people involved in scamming are newcomers, which is due to a lack of knowledge about cryptocurrency, and I have noticed that some newcomers in these forums are not reading the forum rules and regulations before beginning bitcoin/cryptocurrency trading.
Plagiarism Plagiarism, these are one of the things that get most people ban in the forum, anyone who avoid plagiarism have long way to go as a beginner, when you go across of plagiarism/copy and paste threads in meta board, most of users reported plagiarised, 60% are newbies. And a plagiarism sometimes is being committed intentional because the users trying to make a quality posts with copyright. What I note down that causes plagiarism is laziness and inability to research before making a post. It will be helpful to be original author of your work than Paraphrasing someone's work or plagiarised someone's article.
When I first joined these forums, one of the most important things my mentor taught me was how to create a quality post on my own without plagiarizing someone else's work. I still believe that lack of knowledge and research, laziness, and, finally, reading the forum rules increase the level of plagiarism, which is why, as you mentioned, newcomers make up 60% of the meta board.