Roommate turned into Identity thief - among other things, she placed my name on her car title, a new fully paid for car. Can I sue her insurance?

You would have a number of causes of action against this woman, including intentional and negligent infliction of emotional distress.  However, if this woman is a thief there is very little chance that she has any assets that you could collect on if you were to get a judgment against her in a civil case.  Because of that, you will have trouble getting a lawyer to take your case.  As far as can you sue her insurance, the answer if probably no.  Most insurance policies will not cover intentional acts like her criminal conduct so the insurance company would have no liability.  Your best course of action is filing a criminal complaint and hoping the police catch her.  If she is prosecuted successfully, you could be award restitution by the court, but it is likely that you will not collect much.