Feel free to quote me re: Riley. :) I actually ahve a lot of thoughts about him, and many of them positive -- I actually think that if there were a new, more feminist structure in place, I think Riley would do very well with it; he strikes me as someone who needs structure really, really badly though. To be fair to Riley in season five, I think that some of his flameout is precipitated by an actually very traumatic season four -- his best friend and mentor died and he lost his physical strength and his mission, and Buffy is basically all he has left. It'd be as if Buffy lost Willow and Giles and her slayer strength and her calling in one year, and had only Riley -- though what happens in season five to Buffy is pretty terrible, and she doesn't have a military to fall back on. Ironically, his desire to be a Good Boyfriend is part of what precipitates his doucheyness, since if he were less in need of some way to organize his life and were more willing to just take it easy for a few weeks, he would have not spiralled and not hurt Buffy so.

I think that Giles' psychotic break was back in the Eyghon days, and so offscreen in that sense. I also think that the reason Xander's low is not as low as Buffy or Willow's is partly because he doesn't have the power to do much at all -- part of s6 is about the danger of having power, which is not so much an anti-power message so much as a recognition that you have to be aware of the negative influences of power (s7 focuses, ultimately, on the positive side I think).