Allow me to give a shot at answering the questions. I wasn't able to attend the actual chat because I'm in Europe and with my daytime job, I can't afford to miss a nights sleep. Also where I usually can spend quite some spare time on this site, this weekend is a busy one for me.

@GraceNote I never noticed these diamands to be honest and I had to take a look at the site to figure out about them. I always try not to offend/insult/... other people (and I know how hard that can be when so many eyes are reading my writings as on a public website like EE) aswell as to make good arguments. I don't regret any message I made on SE, so I don't see any problem with a diamond appearing next to it.

@GraceNote In my experience, most new users are perfectly willing to adapt to the SE way of working, but the SE concept is somewhat different from most other websites people are accustomed to. Putting in a little bit of effort to get these new users on the SE-track, brings a two fold advantage. Existing users are willing to help find an answer to the question and equally important new users will get better results. I think most of the time it takes really little effort (a short comment)

for new users to improve their writings. I think the Return On Investment (explaining the SE-way in a comment) is usually very good.

@GraceNote Problematic attitude, really depends on what is happening and how bad the behaviour is. In my opinion it is always important to create awareness of what is unwanted behaviour and why I think so.