High levelled players are not always mature or even experienced with the game. Those who have played for a long time have experience, not neccessarily high levels. I have a friend that is level 100 who has absolutely no idea how to find the rules on the website. Level has nothing to do with the requirements to do a good job as a moderator. It is obvious that Jagex has experiment their selection and from my personal experience, which is a high amount, I am absolutely possitive that they do an amazing job. Yes, there are occasionally player moderators who do not deserve status. From my understanding, which is also high, those moderators are very quickly found and demodded.