I'm sorry you're so disappointed with this season! (Just as I'm getting into the show, all my friends are falling out of love with it. *sniffle*)

I agree the "like a brother" comparison was lazy writing, although I thought the ep pretty clearly demonstrated that Cas doesn't mean anything near what Sam means to Dean. By the end of the episode, Dean was already talking about killing Cas, whereas we've seen ample evidence that it takes about a thousand times Cas' level of darkness before Dean even allows the thought of killing Sam to enter his head.

Also agreed that the "Castiel is like a child" is trite and diminishes the potential of the story. *sigh*

Ooooh, imagine Illyria and Castiel having adventures together...! *brain goes off to entertaining places*