I belive it is really easy for us to over-think the relationship between aikido and violence. In America, where everything needs an easily recognized brand or a simple message, it is very easy to get caught up in very black and white thinking.
Aikido either is or is not violent. Yes or no? Either somebody is a criminal or not -- zero tolerance; three strikes, your out. We seem, as a culture, to have lost all sense of degree and perspective. Aikido, for me, instruduces and reinforces perspective and degree.
Very simply, I consider violence to be the act of intentionally causing harm. So, I think boxing is violent, but sport wrestling typically isn't. Using that definition, I experience very little violence in aikido. I certainly don't feel violence when I'm training.
However, we study relationships where somebody wants to do great harm to us. Our practice itself is not violent, but we study violence and how to cope with it.
So, what about on "the street," is aikido violent "out there"? I suppose that if attacked, I may want to harm my opponent. On the other hand, the one time when I had to use physical technique outside the dojo, I was able to throw and pin in such a way that my "uke" was unharmed (I got a bruise from a nearby chair, though).
So, I don't think there is really an answer to the question, but I like Hooker sensei's statement,
The Aikidoka should never harbor intent to do violence on another person.