I think that the "life is hard" theme they had going on would have been a lot more effective if the problems weren't so contrived and, let's face it, easy to overcome if anyone in S6 had a working brain in their head.
Exactly. For instance, I can't take Buffy's money troubles even remotely seriously. The council's money aside, why is she not working at the Magic Box, really? She tried it for a day then quit because Jonathan played tricks on her. Why not try it again later? It's much easier than flipping burgers and apparently the shop is a virtual goldmine, so Giles can pay her well too without she getting the feeling it's charity.
But, Buffy never took the Trio "plotting" seriously because she never saw them as a legitimate threat.
She did that even after they kidnapped Willow and killed Katrina which frankly doesn't reflect well on Buffy's mental capacity. Then again, if the writers had half a clue they would have had someone of Buffy, Willow, Xander and Tara realising the Trio treat. But no, somehow everybody prefers to keep their heads in the sand. It's particularly silly in Flooded where Giles stops Willow from doing a locator spell on the demon sent by the Trio. Apparently he got advanced notice that magic was going to become crack...
Back in the day Buffy took people like Chis Epps and Eric from Some Assembly Required or the Coach from Go, Fish seriously. Why couldn't she do that with Warren, Jonathan and that other moron? I know why - because if she (or Willow or Tara or Xander) did, the plot wouldn't have worked. Treating them as a mere nuisance for an episode or two I can accept, for more than half a season...not so much.
OMWF is pretty much everything S6 is, done right.
I would have to disagree, OMWF suffers from many of the same problems as the rest of the season. Silly plot twists, OOC behaviour (Xander causing people to burn to death), Spuffy, Giles being an idiot, Buffy not even trying to kill the bad guy, etc. I like the songs but the actual plot of the episode is pretty bad, IMO.
I can tolerate depressing stuff easily, I have watched some movies and read certain books that can make S6 look positively heartwarming in comparison. But a show needs to be convincing first. S6 never managed to convince me that the Willow, Buffy, Giles, Xander and even Anya that I knew from the previous seasons would do many of the things they were shown to do. Bad writing, pure and simple. YMMV, and all that jazz.