When things are very busy, there is just no way we’ll see every question. I do try to look at most of them, but some inevitably fly under the radar. That’s why flagging is so important to us. Everyone in the community can help maintain the quality standards, and I love that!
What makes a good mod: A fair-minded individual with an even-keeled personality, who is fairly diplomatic and willing to help out. A thick skin sure helps, too. Mods are not universally loved, heh.
As @Seaofclouds said, we do have a training protocol for new mods. First, they read the moderator’s manual, then there are a couple of hands-on practice sessions with me (by way of IM/chat). After that, there is an observation period…they read every mod email and watch what we do while not actively modding anything, just to better understand the process. Their first official mod action usually takes place while I’m chatting with them, and a new mod is born! ;)