If I were Allie and DH? I wouldn't change a thing. Don't fix what isn't broken. And ignore the naysayers unless of course sales drop off dramatically. Which I don't see happening. Even if they make Xander or Spike Twilight. Actually they'd probably go up due to curiousity factor.

Yes, probably, though given how some of the diehard Buffy comics fans around also seem to be diehard Spike haters, I do wonder if Spike's appearance in the comic would affect sales negatively. That is, if he stuck around.