The thing is, was there ever a "true", original, Kaneki? The way I see it, it looks like he never had the time and space to develop a personality of his own. Yes, the wuss that he was when we first met him was original enough but it was just the result of him suppressing everything. He is like, 23 or what, and he still hasn't really matured at all. Not that I blame him, everyone else and himself too are placing obstacle after obstacle in front of him.
What he needs is to settle down a bit and think about himself, try to find balance with all the mess that goes on in his mind and strengthen himself. And finally start living and discovering what he truly likes and what not. From this perspective I think him staying in CCG makes sense as it serves that purpose. Not that everything will go smoothly but still, it's the best try.
As for the Fool, I think the Fool is supposed to pass through a journey of sorts to finally reach a point or something.