Theymos is the only one that really knows who's suitable, and I think he hasn't made too many mistakes when selecting users. It must be so hard to actually get a consistent, and trustworthy bunch together when most of them are completely anonymous. I think reporting posts shows good intent as its largely a thankless job. Especially, in sections which are already heavily moderated.
I agree and they are not even that popular only with each other. Most are quite unsuitable for any position of power here.
Fairness is the number 1 thing I would look for. Being a moderator is akin to being a judge. You need balance, logic and reason along with being objective and open minded.
And the patience to shift through hundreds of messages all complaining about the forum in someway. Whether its about some other user or themselves being treated "unfairly".