I think his connection to his family is over and they never take his money, unless they don't know it is from him. I don't think the ricin is for Walt, he might as well let the cancer get him. I don't know if Walt wants to kill the Grey Matter people or not. They screwed him out of his lifes work, but I'm not sure if that would be enough for Walt to kill them. Bazooka is for Todd and the Nazis.
Walt dies from violence, but gets what he wants to do done when it comes to his final plan. I have no idea who the ricin is for. I don't know how he could slip it into anyones drink/food except maybe the Grey Matter people.
Interesting note and maybe mentioned and I missed it. Walt and Jesse could pull something off together. Those two only have each other if they could work together and possibly Todd. Who knows.