I can totally understand people rooting for Walt and that's what makes the writing (and acting) of the show so brilliant. We have a man, a coward, who never had the guts to take his chances in life even though he was brilliant in his field and it wouldn't have taken much for him to succeed. He is caught in a dead end job and then get's a different kind of chance to prove himself and he slowly begins to transform when he realizes his gambles and risk taking pays off and he gets the respect he believes is owed to him. From then on everything spirals down. Now the vile things he does are always presented with a twist for the viewer so he can decide if he's right or not. Tuco is a bad guy, one of the worst and his near paralyzed uncle didn't seem better at all (he wasn't as we find out later) so killing him is justified, right? Walt running over the two drug dealers who killed the kid dealer before is justified, right? Jane.. ah, here it get's tricky for the first time in the show. Well, she turned out not be a very nice person and she dragged down Jessie with her. She threatened Walt to expose him (and she may have taken all his money in the end) so Walt let her die. However in this case.. was she really a bad person? She was a junkie, an even worse one than Jessie but does that make her a bad person? She could have been helped as her dad tried to help her but this time Heisenberg took control for the first time and there was little justification, if any at all, for Walt to not save her. Yet the only thing he really cared about was him and the negative impact she had on his life by threatening to expose him and by taking down his partner which would have made Walt's life more difficult. There have been other instances later in the show that had similar ambiguous scenes but i believe Jane was the first time anyone should ask himself if Walt is just a good guy who went too far or if he had lost it. The writing was so good on the show that even in the penultimate episode where he slowly withers away in that cabin and is in desperate need of some human company we are trying not to feel sorry for him and many do but i can't fault them. Even after all he's done, all the lives he ruined for his own ego we can't deny that we feel sorry for him at that moment. As to Hank.. i believe he's the mirror to Walt in a way. Hank was a capable cop but he was out of his league when he got the chance to "play" with the big boys in the big league. Better to be a big fish in a small pond than a small one in the ocean (forgive my bad metaphors ). However the one mistake he made was that he didn't bite the bullet and come clean and ask for support from the DEA office but at this point it also became personal because Walt had been doing his business for so long under his nose and he never suspected anything and that just destroyed his ego. He might have wanted to save his job in the process but it was revenge too.. in that regard Ahab Hank is not a too far out moniker but i'd not call him a villain by a long shot (they way he went down was anything but villainous).