Is obedience obligatory to a father who molests his children and his son's wife, and is not speaking to him considered an act of disobedience?

If what was mentioned about the father's harassment is true, then it is a great evil and a major sin. He should be advised and reminded of Allah, and the dire consequences of these actions should be explained to him. If he repents, then praise be to Allah. Otherwise, the wife should treat him as a stranger, veil herself from him, not allow him to be alone with her, and threaten to expose his affair and report him to the authorities. As for you, you must enjoin good upon him and forbid evil, prevent him from harassing your wife, and be dutiful and obedient to him in what is good. It is not permissible to disobey him unless he commands a sin, and it is not permissible to abandon him. You should also supplicate for his guidance.