Vito pursued the best available options to secure a relatively good life for his children.

Santino was never going to be anything but a gangster,and Vito knew that for the Corleone Family business to survive, Sonny had to be the one at the helm.

Vito provided for Fredo,the weak and dimwitted son by placing him under the protection of the Molinaro Family. He would still have an income,but would never be a target for a takeover by any rival Families, since no one took him seriously as a potential leader.

Initially,Vito wanted Mike to pursue the legitimate world,and I believe that he would have used any of his influence and resources to bring that about.
When Sonny was killed,Vito realized that the future of the Corleone organization now rested squarely on Mike's shoulders,and acted accordingly.

Even though Tom was not blood,Vito knew the value he brought,and made sure that his hands were kept as clean as possible.

As far as Connie,she was not a "masculine child" and in the old school mentality that Vito possessed, her job was the 4 C's (cook,clean,children,church) I believe that in the novel,Vito's solution to the domestic violence in her home was that she should not give her husband a reason to beat her. Once she married,she no longer belonged to her Father,but instead,to her Husband.