Eccentricity is not necessarily a bad trait to have. Sounds strange? Well, if you just want him in a conventional GK role, then yes it is an unnecessary burden. But if you want him in a more adventurous role like a sweeper keeper, then it is not a bad trait to have, provided you have the other requisite mental traits like creativity and decisions. You don't want an eccentric freak who is an idiot as well.