I would say he needs to speak to his doctor, but it also sounds like it could be boarderline personality disorder, which causes a lot of similar issues to bipolar but primarily in relationships. The on again, off again way he breaks up with you over little things is what makes me think this. Also, he could have more than one issues happening at once, so he does need to see a doctor since it is effecting his day to day life.
Well sometimes extreme anger can come from an agitated mixed state which has the speeded up quality of mania but the down aspect of depression. A lot of the other issues you described (impulsivety, sleep disruption) can come from bipolar as well though only a psychiatric could provide a conclusive diagnosis but it would be helpful for him to see one.