Well the issue isa family issue and unless the adults in the family are willing to step up to the plate then forget it. Your mom acts like an abused woman and NEVER challenged her husband openly. So how do you deal with this - I would suggest talking with an abused women's hot line or shelter for strategies that have worked for others.
I would suggest for such a man the idea that this would become public would be his worst fear. So any risk of public knowledge is a leverage to get his permission to take corrective actions. I would suggest your sister talk about his issues to a school counselor who will be bound to see this for what it is a seriously compromised child and then they will push for intervention Alternatively you can consider your fathers actions emotionally abusive the report the situation to family services and then watch the fireworks because there will be.
A brittle controlling personality such as his will never react well to strangers asking personal questions.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.