Well, he's a smart boy. He's noticed that in your house, everyone is either an abuser or a victim, and he sure doesn't want to be a victim! Only other choice is an abuser.
Until he sees more choices in your household to emulate, he'll be an abuser.
Young children always pick up adults' behaviour and language and from hearing it from the television or elsewhere.
You need to speak with your son and tell him that his behaviour is unacceptable and that you do not like it. It will be difficult for him to stop doing it if he has been "naughty" for some time, but in time he will eventually stop. You need also to ensure that he is not exposed to bad verbal language or behaviour.
Children only mimick what they hear and if he hears bad language, he won't understand that this is wrong.
You need to be firm with him and not give in to his demands. All children will throw tantrums if they do not get what they want, just don't give into him. Put him in his room when he is having a tantrum and leave him until he calms down. Once children are in a tantrum (same for adults), they can't immediately stop, so you just have to leave them until it passes.
Hi there. Well, sweetie, why are you living with a verbally and 'sometimes' (one time is too many) physically abusive man? Clearly that isn't good for you or your son. That is dangerous to you both. Yes, that impacts your child negatively. yes, that makes for a rotten home life. Yes, your son deserves better. You need to leave this man. for your sake and the sake of your children. good luck