Is it permissible to boycott one's father to avoid his slanders and machinations, knowing that he disinherited his children and falsely accused them?

Disobeying one's father, shunning him, or treating him ill is not permissible, regardless of his actions. This is because Allah has commanded obedience to parents and kindness towards them, even if they are polytheists, as stated in the Qur'an: "And We have enjoined upon man goodness to his parents. But if they endeavor to make you associate with Me that of which you have no knowledge, then do not obey them. To Me is your return, and I will inform you about what you used to do." As for disliking him and not loving him in your heart, there is no blame in that if it is beyond your control and he is the cause of it.