On a basic level, the idea of certain sandboxing, i.e image and link posting restrictions along with rate limits for new accounts and new instances is probably a good idea.
However, I do not think “super users” are a particularly good idea. I see it as preferrable that instances and communities handle their own moderation with the help of user reports - and some simple degree of automation.
An engaged user can already contribute to their community by joining the moderation team, and the mod view has made it significantly easier to have an overview of many smaller communities.