Even though you seem to have no evidence that this guy actually has harmed his kids, there is certainly a good chance that he has. His attitudes sound classic perp to me: he's into control and use of sex as a humiliating weapon, he's disrespectful of boundaries and incredibly selfish, he is cruel, and he seems to be dealing with a whole load of personal issues that cloud his judgment in dangerous ways.
What to do? Maybe the answer lies in how we all remember how it felt to be alone, unseen, unhelped, and silenced. A child being hurt by his own father will not have the resources to reach out for help. Someone else has to reach in.
Nobody living can ever stop me
As I go walking my freedom highway.
Nobody living can make me turn back:
This land was made for you and me. (Woody Guthrie)