AD-Buffy is aware that Giles is male, and attractive, but also aware that he's not for her. At least not that way. It's a Giles-Buffy partnership story. It's season 5; the relationships among the Scoobies are healthy, and the threat is external. But Giles' role among them is shifting because of the sword, especially his role with Buffy, and thus they must adjust. And then there's the mutter mutter issue, hinted at in part 2, which part 3 makes clear.
There are several editions of Giles co-existing in my head, some of them harder-edged than others. I've known this for a while. I was interested to note that my internal Buffy has begun to take on variations.
There are some similarities. I tend to class Buffy as a tactical thinker (assess a roomful of threats accurately; make judgments on the fly about immediate combat) and not as a strategic thinker (putting her in charge of larger battles or campaigns would be a mistake; that's what Watcher-training is for). Also that she has completely trustworthy instincts about who's evil and who's not. And that her #1 repeated mistake is going to be not trusting the people around her to help her, even when they've proven over and over that they can.
This is exactly the thing that fanfic gives you that standard writing does not. If I were to write a series of stories about an original character (which is, btw, exactly my goal in the next year), I would aim for consistency of character. Or a single growth arc, perhaps. I would not write variations on the character. Or write several takes on how the character would act in a fixed (canonical) situation. But we do this in fanfic, and enjoy it.