I was just wondering if someone can help me with some of the strategy here.

I just talked with the police and they said, like you implied, that putting his hands on me is battery, regardless of how violent it was.

The disadvantage of filing a police report is that it will make my roommate much angrier and more hostile, and making it even scarier to live here while I'm waiting for the situation to be resolved.

Maybe the threat of filing a report could be used? I could explain to him and the landlady that he committed a crime and that if it happens again I'll file a police report. It would be nice if threats could be used to keep them in line. And maybe a threat is all it will take to push the landlady to action.

Also I am wondering if there is tenant law i could use as a basis for suing the landlady for providing an inhospitable environment. This is not really to win the suit but rather to force her into action.