So, among 2300 registered users, there are +/- 100 active users who regularly post, read, talk to other people, invite other people, practice interlinking, learn Markdown: someone more, someone less.
But it’s obvious those skills are not what we’re looking for when choosing a mod.
What are the top 3 characteristics of people that one should grant mod permission?
How mods are different to Level 4 users in terms of their goals and skillset?
How many mods a community needs depending on its activity and other measurements?
above all else, they must participate heavily, and plan to do so for a long time in the future
even temperament and patience are huge
Beyond that, I strongly advise that you have several moderators and make sure they check with each other on anything difficult. If it is straightforward (obvious spam) then they can obviously handle it alone, but when things get hairy, they should have a policy of checking their response with at least one other mod to make sure they are setting the right tone.
I had not moderated a forum for a few years and looked to that site for a refresher on ideas, and generally find his advice and commitment to the topic excellent.