I'm all for making the game fun---even if that means empowering players with more control over their characters.
Sure, and I'd agree. But you also have to consider the attitude this player has come at this from; Rechan has said the player basically wants this character concept and nothing else.
If he had said, "Y'know, I really like the idea of this, can I play something like that and figure out some way it can be accomodated?" then I'd probably be ok with it and work with the player.
But this guy sounds like he's just shoe-horning himself into the game irrespective of others feelings or needs or wants.