The Question and Answer section for Schindler’s List is a great resource to ask questions, find answers, and discuss the novel.
While the Jews are carrying their personal belongings to the ghetto, Schindler is busy making deals with Jewish businessmen. In essence, he's taking advantage of them, but there's another side to it as well.... he's making it worth their while by...
Mrs. Schindler leaves because her husband doesn't care whether or not she stays. His mistress is installed in Krakow, he's overwhelmed by business matters, and he's dealing with the Nazis. Thus, when she asks, he says nothing.... and she leaves.
The Jews living in the countryside were ordered to the major cities, including Krakow, by the Germans. They were forced to relocate and register their families by the Nazi regime.