She even gets mad when you point out the Keeper dying was kinda her fault. She prefers when you say Marethari was a fool. But like, she saved her. The demon would have for sure possessed Merrill. I don't buy for a second she'd be strong enough to resist a Demon. She didn't in the fade. We've seen she has no problem accepting their "help". I agree Fenris and Anders went too far at times, but it pissed me off how she refused to take responsibility for anything.
I kind of have to agree - I liked her as character, didn't like her as a person. I didn't even mind the fact that she was a blood mage. I don't really think blood magic is inherently evil, and I think it could even be a useful tool in the right hands. But, she wasn't it. She was sweet, sure, but I also found her naive, gullible, incompetent, and stubborn. My last playthrough, I rivaled her and at first it was hard - kind of felt like a kicking a wounded puppy or something - but in the end I felt like she needed it.
Also regarding Anders, I'm probably in large minority in being a fan of his (and I can see why people don't like him - it just happens that I do), but a lot of times I felt like he said the the things I wanted to but didn't. He and Varric get along fine, and he's never cruel to Bethany (I actually double checked the wiki, and all their banters are friendly).