Carl killing the governor would be unexpected--especially if he does it to defend Rick, only after Rick and Carl are dealing with tension.
But that's pretty much what already happened with Shane.
Yeah, but there was not the tension between Rick and Carl as implied by the preview of today's episode. Not to mention Beth kissing Rick (even if innocent) may not have been lost on Carl, but we will have to wait and see about that.
Yes, but at some point, pieces can be lost that sufficiently devalue the entertainment experience. Daryl's my favorite character on the show and I just don't see the remaining ones holding my interest as the show currently exists.
that's where the writers have to step in and continue to develop the original and new characters, so in the event Daryl is killed off, you will have growing storylines/arcs to keep the audience interested. In theory.