I think it's essential that the Council doesn't get too mono-brained - that's how the old one went bad. So an irritant like Spike is very healthy - but I think it's also why he goes for the whole Delenteria Quest thing, to have something that's just his. It's fun to write these small conflicts - like Vi really disliking Illyria - that don't cause the thing to fall apart.

The Shanshu is the most backhanded prophecy I know. And that's saying a lot. My personal canon is that it's not humanity at all, that the prophecy means something else (or at least the chance to have died back when your human body died). So it's an illusion, and Angel signing away the shanshu was the smartest thing he ever did.