I really like the insights you show here and the comparison of her relationships. I have always felt that each of her relationships were showing a different need in her that had to be filled until she could move on.

I do not believe that she could never have a relationship with Angel again. They would actually have a lot more in common now than they ever had before. It would, however, be a hugely different relationship than the one they had previously. But, the same would apply to Spike, so there we go.