Jay Pretty spot on - you’ve nailed all that’s salient very succinctly.
One major comment: Give users an idea of what urgent is - data loss obvs, not being able to login in, ++. Otherwise everyone’s bug / feature is urgent ’cos it’s just occured to them. Indications will help to calm things down.
Minor: There’s a double ‘period’ at end of How to triage para.
Re: Forum features: I really like this 👍. Maybe it’s a separate sticky for other people to add tips and tricks? And / or has a link to 3rd party doc ‘Flarum hints and tips’ (or similar)?