According to the laws of my country, the 1st and 3rd case is most suitable to start a divorcing process.
In the first case, the husband hasn't supplied the family with anything, left his wife with children, even though he has money to at least send them financial aid once a month, that is, assuming the info about oil-company is true. According to the law, Mrs Manroe, if not divorced, has rights to demand financial aid from her husband, with whom she's still officially married.
In the third case, the violence against another human being, let alone against oneself's house spouse is enough to file a lawsuit, because it is the violation of human rights (if it wasn't used as a self-defence mechanism). But according to the information that Bob Tanner was a drug user, we can conclude that the aggressiveness towards his wife was most likely intended to harm her. His deeds threatened her life, physical and mental state, so she/lawyer can start a divorcing process to save wife's life and avoid such situations in the future.