Totally agree with your points.
We tend to do these things. As I moderate 2 forums the principle is the same.
You could start by sending a PM a friendly reminder to user(s) that instigated the problem and send what is expected of them in a public topic
- Repeat offenders get official Warning
And moderation guide follows thorough
We sometimes close topic as a cool down period and it opens a few hours later. Similar to a system flag topic closure.
We normally let discussion run under watchful eye and when flags start to pop up frequently moderators step in. Basically the members define the ‘stepping over the line’