See, the thing is, I didn't see any of that on screen. For example, you speak of how Buffy must have felt in response to Tara's death--but I never saw any reaction whatsoever from Buffy toward Tara's death. A day or two after Tara died, Buffy was walking out of a grave into an arborium and grinning, showing no concern whatsoever for what had just happened to Tara (or the fact that Giles was probably dead and Xander was missing). You can fanwank all sorts of reasons why Buffy did what she did and what she might have been feeling inside, but if it's not onscreen, who knows what she was really feeling (if anything).

Of course, I respect your right to disagree.