Skin Blues wrote: And if Walt was going to poison the kid, why not just kill Jesse like he did Gale instead of beating around the bush with the little kid?
You'd think so, though Walt's always had a loyalty to Jesse that has proved detrimental at times. Remember that Gus never wanted Jesse in the first place, but Walt demanded his involvement. That said, I still think he would be willing to use him as a pawn against Gus.
And this is kind of beside the point, but how complicated could this meth making procedure be that nobody in the world can just follow the instructions, like the way all other chemicals are made? Unless Walt flat out refuses to give away some key aspects of it, but a little bit of torture and family threats would easily get that out of him. I understand it's kind of the crux of the show, that these two are the only ones who can do it, but it's not very realistic.
Have to suspend your disbelief a bit, I think. Walt's methods and level of purity are apparently unmatched, but why meth addicts would care much about that, I'm not sure. Of course, I'm not a meth addict.