I can see no reason whatsoever to have the spine out of line with the guide placement. Place it on the same side or place it opposite the guides, but place it anyplace else and the behavior of the rod will be asymetrical. Perhaps there's a valid reason to to this but I sure can't think of it.
FT, Nice argument but no sale. There's no slot or keyway and the term refers to the entire blank -not its components. But I agree it doesn't matter much (except for good language usage) as it will be undertstood by most fisherman.