Walt telling Jesse about Jane was not heartless twisting of the knife, but actually the start of Heisenberg turning back into Walt. The moment he let Jane die was the start of his true descent, and he's telling Jesse about it now because he's explaining why he is letting Uncle Jack take Jesse, he is deciding to save Jesse when he could have let him be killed right there. As with Gus and the cartel he's going to shake hands with those who killed the ones he loved, but he's already planning his revenge.
The only ones left justifying the firepower of a heavy machine gun are the Aryans, so I think a sit down with Lydia to get the location of their meth lab, then the Ricin in her tea and she's done. Then the Scarface ending to free Jesse.