Buffy's mental health issues are really fascinating, and, as you say, they're there almost from the beginning. So physically strong, so emotionally fragile, our Slayer.

I try to keep track of BtVS "therapy" fics, which run the gamut from ridiculous to sublime, since it's something that IRL would be a MUCH bigger part of the story.

I never really saw Spike's comforting of Buffy in "Touched" as evidence that women will ultimately betray one another, and a woman's most important connections are with men. Partly because it's her entire support network that rejects her in "Empty Places", including Giles and Xander, so I don't see women as being the sole betrayers. Since Buffy does immediately reconnect with her "girls" it doesn't seem like an idea that lasts, anyway. (Sidebar: Dawn's betrayal is the most shocking to me. I think it's the payoff for the "Buffy won't choose you" planted back in CWDP — it's Dawn that doesn't choose Buffy, which is probably what The First wanted all along.) Spike is important to Buffy certainly, but to me it reads more as "your lover/mate/romantic partner is your most important connection". This breaks down somewhat more obviously in "Grave", when it's Xander that saves Willow after the death of her lover almost destroys her.

I know people have trouble with the "violation of personal agency" in the "Chosen" spell, but I think that was very much an unintended consequence. In "Bring On the Night" Giles says:

Potential Slayers. Waiting for one to be called. There were many more like them, all over the world. Now there's only a handful - and they're all on their way to Sunnydale.

To me, this implies that the Scoobies' good faith assumption was that they had ALL the potentials on site, and that those WERE consulted and had given informed consent to the activation spell. They were wrong, of course...but isn't that the way of all good intentions?

I've wandered far from your main points about Buffy's depression, however. And they are good ones.