Would it be illegal for me to not inform him of where I am going or where I am at even after the child is born?

You don't have to tell him anything. However, he can sue you in Court for parental rights and then yes you would have to tell him and the Court could order you to allow visitation, as long as the Court believes that he is not a danger to the child. I would just save your self the trouble and let him know about the child after the child is born. If you are afraid for your safety or the childs safety then let the police the know.

He may be a terrible person and you may want him out of your life forever, but remember he is the baby's father and he has the exact same parental rights as the mother. (If he would be a danger to the child than that is a different story).

He is a very mild-mannered person, but once he starts drinking alcohol or smoking he has a very hot temper. I don't think that's healthy for me or a child.

Then, if he seeks custody or visitation of the child you can let the Judge know.