While institutionalized power-over is antithetical to anarchy, I don’t agree that any power-over is. Some of the conflict here comes from the understanding power-over as a negative or threatening thing. In my life there are many forms of power over me that I want. I have friends who are smart and socially connected and their acceptance is important to me. I have lovers who I feel a draw towards and desire to be taken over by. I have working relationships that expect of me commitment if I am to stay involved. I have physical limitations that I have to find ways to work around. All of these things exert manipulative, and some physical, power over me, but I enjoy them, and I improve and expand myself because of them. My personal history also includes a number of violent intimate relationships. There are times I have been hit that were far less damaging than some of the things people said to me, or the way/context in which they said them. I think this ties into the issue dot brought up; what kinds of influences over us are we ok with? not ok with? why?
I agree with what aragorn said, that the desire for violence is a human one, and a part of the human project. In anarchy, violence might be added to the list of types of power-over that could be enjoyable/productive/inspirational. When violence did not evoke the power-overs of bureaucracy, policing, gender, race, access to food, water, shelter, medical care, etc, then it would be different. Physical violence might end up in the long and confusing list of influences like chemistry, charisma, obsession, and so on that give force and direction to our individual experience.