Prison is where you go when you commit crimes. Skyler committed crimes, and that's not Walt's responsibility, it's her own. And even more inexcusably, she had more opportunities to get away clean and was aware that she was all that stood between her kids and the blowback of a criminal parent.

But just as Walt turned down Elliot & Gretchen out of pride, Skyler backed off on her lawyer's recommendations. She refused to give the police officer who responded to her call that slightest excuse he begged her for to kick Walt out. And Walt had nothing to do with her choice to cook Ted Benneke's books, or her subsequent efforts to cover it up that put Ted in a hospital. He did nothing to force her unconscionable and disgusting efforts to obtain the car wash and degrade its owner. That stuff was all in aid of Skyler's pride and ego. She wanted the car wash, because she was used to being in charge and the one who called the shots in their marriage, and Walt's newfound indifference to her authority impelled her to soothe her pride by asserting herself in some fashion. She did so by citing her non-existant financial expertise and shot down all of Saul's proposals (you notice that for all he is played as comic relief, he's usually right), so her prestige in their little conspiracy was staked entirely on proving her suggestion to be right. So she used mob tactics to coerce a man to sell the business he spent his life building up, and then fraud to chisel him out of even her estimation of a fair price. Her claim that "we don't do that" was a perfect echo of Walt's own attempts at drawing arbitrary moral distinctions early in his career.

If Walt's rationales of self-defense and survival for much of his later actions are undermined by the point that he should not have got into the meth business in the first place, so too are Skyler's defenses.

A lot of Hank's problems are his own fault as well. His tragic flaw is his tendency to go rogue and do things on his own. That's how he found himself alone against Tuco, unarmed against Marco & Leonel Salamanca, and stuck in the desert with only Gomey to face down half a dozen thugs.

Yeah, the widow of a DEA ASAC killed in the line of duty, who already has made a scene reaming out his one-time boss for letting the cartell take a shot at him once before is going to be without protection? I don't see that.
Just because an embittered old dirty cop said it, does not make it true. From day one, Gus was in bed with the Salamanca cartell and all their dirt. His dealers used children and murdered a child to cover their tracks. He got innocent delivery drivers killed by having them transport meth in chicken delivery trucks. And from the minute he hired Walt, he tried to estrange Walt and Jesse and play them against one another. Walt was not being paranoid, he called Gus' play right down the line. He was right on target about Gus, from his using Hank against the cartell to Gus' plan to kill him and replace him with Gale. He tried to work with Gus, he respected Gus and he got in trouble with Gus because he would not turn on Jesse.

Mike was caught entirely by Mike's own mistakes or personnel, with whom Walt had nothing to do, due to Mike's own efforts, and he was embittered, and like any Breaking Bad character, sought to pin the blame on anyone but himself, so he spewed that garbage about everything being Walt's fault for killing Gus.

Meanwhile, it was Jesse's paranoia that directly got Hank killed, because he chickened out of confronting Walt in public while wearing a wire, and instead, engineered the desert confrontation. He believed Walt had a hitman waiting in the plaza, but could not believe Walt would not call in muscle to retake the money that Jesse believed Walt valued most?

Walt saved his life, more than once, from his own self-destructive tendencies. Yeah, he's a mess right now because of Walt, but he'd be even worse off a long time ago without Walt. Jesse was a weakling who let other people control him and surrendered all agency. Walt is the only one to build him up, and his actions recently proved it was not out of purely selfish motives. Long before Walt, Jesse was selling short his potential (remember his NA story about the box he made in shop class that he later sold for weed). It was Walt who pushed him to realize a portion of that potential, which he kept flushing away. He took up with Jane and let her get him on heroine and went along with her blackmailing Walt. He created the situation where Walt was motivated to let her die, rather than going the extra mile to save a piece of junkie trash who made open-ended threats against him. Walt got Mike to clean up the scene and protect Jesse and he paid for Jesse's rehab. Walt wasn't the one who stole meth from Gus to sell at NA meetings (talk about self-destructive behavior), or the one who invented moral outrage at the connection between Gus and the death of Combo and Andrea's messed-up family to pick a fight with Gus. It was Jesse who harbored immature resentment at Gus taking the majority of the profits (all he did was build up a distribution network, and pay for the trucks that delivered meth, the laundry to conceal the lab, the super-lab itself, and all their supplies and security costs), which led him on the course of action that fractured the initially positive relationship between Gus and Walt.

And then, after Walt is in dutch with Gus & Mike because of what he did to protect Jesse, Jesse lets himself be seduced by Mike and brought to his side and lashes out in a rage when Walt correctly points out their agenda.

It doesn't remotely justify Walt's poisoning of Brock, but it took a lot of Walt repeatedly bailing out Jesse only for Jesse to keep falling into dissolution or endangering them both before finally going over to the enemy, to bring him to the point where he was willing to endanger a child to scare Jesse away from his newest replacement daddy figure (note that Jesse seems to have forgotten his moral outrage about the kid's and Combo's deaths, once Gus & Mike start flattering him).

There are nothing but scumbags in the Breaking Bad universe, outside the DEA and Schrader family and since Walt was trying desperately to save Hank on more than one occasion, I am totally cheering for anything he does against Uncle Jack & Todd and the rest, and won't care very much if he puts a couple of rounds in Jesse to boot or Skyler goes to jail or Walt Jr has to live with Aunt Marie (or even foster care). When one of your parents pulls a knife on the other out of the blue, and you side with the cutter, over the victim, you pretty much deserve the lumps that come with it. For Skyler to believe Walt is a genuine threat at this point is ludicrous, she was simply seizing on the chance to play the victim to an audience of Walt Jr, and establish herself as the good guy rather than the co-conspirator who traded her children's safety for Walt's acquiescence to her car wash scheme.