Err I agree with like 2 of these. Badger and Skinny Pete are probably correct.
Gretchen is most definitely an INFJ though, not INFP. The way she dealt with Walter's lie about her and Elliot paying for his medical expenses was completely Ni/Fe. She didn't have a strict moral opinion on the general matter of dishonesty; she tried to dig deeper and figure out why Walter was lying and see things from his perspective. Fi would likely never do this; it would probably feel betrayed and ethically opposed to being an accomplice in Walter's dishonesty. Ni, on the other hand, is much more capable of seeing things in context and forming a judgment from there. She didn't take things personally, but rather, gave Walter the benefit of the doubt because she sympathized with his tough position and understood that there was a logical appeal to be made for his actions (Fe/Ti).
Jane is INTP, not ISTP. An argument could even be made for her being ENTP. Either way, she clearly leads with Ne. The conversation she has with Jesse about the Georgia O'Keefe museum when she explains why O'Keefe drew a door over and over epitomizes Ne. Jane and her Ne, unlike Jesse and his Se, understands that a door can be creatively connected to a vast number of ideas, so only one painting of a door does not suffice.
Tuco is ESTP to the max. His Se is just completely over the top, and he as no Ti to mold him into some rational, moral character. He is impulsive, aggressive, domineering, and thrives on intense action and the thrill of the moment (this explains his addiction to meth). The scene in the junkyard where Tuco, his minions, Jesse, and Walt make the deal does a really good job of exemplifying Tuco's type. When one of his minions makes the point to stand up for Tuco, Tuco is unreasonably insulted, and before even thinking, he follows his impulses to just beat the shit out of him (Se). He is insulted because his employee upset the social hierarchy of their little drug cartel (Fe). Tuco was the boss, so no one under him should do anything that implicitly undermines his authority. I will admit, however, that he is one crazy motherfucker.
I have no opinion on Elliot's type. He seems to have some Fe going on, however, and I'm fairly certain there's Ni, so ENFJ might not be too far off.