Now this I can see happening. It's weird thinking how Skyler would ultimately ingest the ricin after seeing it there randomly, but the Jesse-ricin link is where I believe Walt's relationship with him will start to disintegrate.
Walt keeps his family and Jesse completely separate. If there is something Walt doesn't want Jesse to know, he won't know it. I don't see that happening. The ricin will come in handy the next season/other half, not now. They need to let the viewer forget about it. Maybe they might not even use it. Too predictable and too much of an AHA! moment for BB.
His decisions are the antithesis of logical and always have been. Every one motivated by greed and ego, not logic. Id, not ego to get all Freudian. The show has manipulated you into thinking they are logical, though.
That's what makes this show amazing, and what will make it go down in history. It forced people to commit to and invest in a false image of its protagonist.
That's why, ultimately, this show is better than its closest counterpart: The Sopranos. In The Sopranos, Tony and Carmela had a very similar dynamic to Walt and Skyler. But a) Carmela always knew what she was getting into, b) the mob was all Tony ever knew, c) Tony legitimately loved his family in the best way he knew how. Though the thrill and prestige of being the mob meant a great deal to him, he didn't have many options. It's safe to say he wasn't going to find a career making similar money. He wasn't going to walk away from the business. Tony was man with a ton of heart and love but limited in his ability to understand it or show it.
Walt was a good man, good father, and a complacent but endearing husband. But he was absolutely miserable doing all that. When given a death sentence, he was given freedom to end his life providing his family with SECURITY, being the man he best knew how to be, very similar to Tony. A good man. As time progressed, his health stabilized and greed took over, we saw him slowly desire more, still with the intention of providing for his family. It was when he met Gus, that I believe things changed. He saw a man of similar stature to himself. To the world, Gus was everything that Walt was. A gentleman of few words (though Walt has been getting loud lately, the cars for example), mild mannered, etc. Walt saw this and saw the power Gus truly had and was drawn to THAT. That was the end of Walt. Walt is a power hungry man.
Tony Soprano is not a power hungry man. He, like Walt, is scared, alone, and vulnerable. But unlike Walt, his bravado is to prove it to everyone else in hopes to prove it to himself. Walt's already proved himself. There isn't a doubt in Walt's mind. And now he's literally asserting it to everyone else.
So both are anti-heroes, nearly border lining villains at some points, but Walt has clearly overstepped that line a long time ago. Which makes this the more interesting show, because he is still the most interesting character and the character you want to see prosper. You've watched his struggle and YOU, as a viewer, feel like he justified and deserves the money, his family, his power, etc. As much as Walt does.
