Very interesting analysis. I actually don't think it's all that hard to reconcile Angel's and Spike's soul stories, but that's a whole separate discussion. Regardless, it makes a lot of sense when you tie it to Buffy's character development, and I can see how, based on this analysis, you expect Spike to show up in season 8 to complete Buffy's arc. I still don't think it's going to happen, though.

But since you've included Riley in your analysis, I'm curious what you think of Buffy's relationship with Satsu, and how that fits into her acceptance (or lack thereof) of her demonic side. Here is someone who is not just a mirror, but actually in the same situation as Buffy. Does that show further acceptance, or is it a step backwards?