Lol alrighty. 
To become a [volunteer] moderator, you have to first and foremost demonstrate your maturity and that you're a responsible individual. Second, you have to contribute to the community, such as posting guides and responding to those that need help. Third, you need to show an interest in the game lol. (Kinda obvious, but it wouldn't make sense for a person to be a moderator if he/she doesn't want to play the game.) After a while, you can post a resume to any of the game staff (such as Brice) of your qualities, past experiences in moderating (if any), and provide your own definition of what you think makes a good moderator.
A moderator's task is to oversee that everyone's posts do not violate any of the rules, as well as manage threads (for instance, move a thread to its appropriate board if it was misplaced).
At the moment, moderator's don't really get anything special ingame (as far as I know), but the ability to modify posts/threads and to have a PS MOD image tag on your name are special enough in my opinion.
LOL of course Moderators can play the game! They just don't have GM (game master) abilities though.