This site is great! One thing I would suggest is something similar to SO where users are able to edit other user's posts. I believe this will be extremely helpful especially for newer users who are not as familiar with the typical format. I am not sure if this is something that will be available to users once they reach a certain trust level, as I am still at the "basic user" level. If its not, I believe this feature will allow the community to help moderate the site, and in turn reduce the workload on the RStudio team.
According to the Discourse user trust level documentation, editing all posts requires being a "Leader", the level 4 trust level that is only available as a manual assignment. Someone at level 3, ("Regular"), can recategorize and rename topics, but that's a dynamically assigned level that will take another month-and-a-half or so minimum before people reach it organically.
While I think it's appropriate for StackOverflow, the only real use case that I'd personally be comfortable with here on an ongoing basis would be formatting issues. If that is an ongoing problem, maybe RStudio will decide to recruit a few community members to help out. In the mean time, formatting issues could either be resolved with a reply that does it for them, or a PM advising them on how to fix their post. A PM about a specific post can readily be done from the flag button hidden by the dots menu in each post, which gives you an option to PM the user directly.
I agree with you that it would probably only be appropriate for fixing formatting issues. So while the site is in its infancy, it might not be much of an issue. However, as it seems the general goal is to eventually migrate all questions that would be posted on the discussion boards, I think the site will eventually start to see a lot of questions from newer users. IMO these newer users would most likely benefit from the help of the general community in formatting their questions to better help their chances of finding a solution.
I think waiting (a few months?) until there are folks at level 3 before promoting to full edit powers will be fine.
Most users here are (like me) not experienced enough with Discourse to have a sense for which powers are more or less exclusive/sensitive, but they will if they gain them organically according to the rules in @nick's link, similar to the experience on SO.
The powers are already quite great at level 3:
Recategorize and retitle threads
Visit a "lounge" to ping staff when other edits are needed