I can't help you I'm sorry to say but I'm glad you posted this. I have a very similar thing that happens occasionally. The punching part at least. I don't know where it comes from. There is no emotion connected to these impulses for me. By that I mean there is no anger at the person or even reason to want to hurt them. I'm not really a violent or angry person and the idea of hurting someone is really repulsive to me.
It doesn't seem like an impulse control problem... more of an unwanted and inappropriate thought type thing. I don't have much problem resisting the urge to just punch someone for no reason. It's still very disturbing to me. Sorry... I don't feel as if I've helped you unless knowing you aren't alone makes it easier to accept these impulses.