Is the father's decision to expel his son from the apartment he owns, as a disciplinary measure after his repeated assaults on his siblings and parents and his causing physical harm to one of them, and is this decision sound Islamically?

You must supplicate for the brother, as his actions are foolish, reckless, and aimed at corruption. He must hasten to repent, and he should be advised and guided. The father has the right to expel him from the home if he fears his harm or if the expulsion would deter him. However, if it would only increase his stubbornness, then it is better not to do so. The estimation of benefits and harms is left to the father. The mother must be patient and supplicate for him often, for the supplication of a parent for their child is answered.