Re: causing no (serious) harm
I remember when I was with Maruyama Sensei that he always stressed that technique should be effective but that going out of one's way to injure an adversary was wrong. I teach my students the doctrine of least possible harm. It is my view that if walking away from a situation will avoid conflict then that is the correct technique to employ. If immobilizing an opponent will end the conflict then there is no point in injuring him. Of course least possible harm can escalate to killing an opponent if the situation warrants. It is our responsibility as practitioners of Aikido to determine the correct response to a given situation. Gravely injuring or killing a person when a lesser response is adequate to defuse the conflict and then blaming it on an 'instinctive reaction' is unacceptable. Why else are we training if not to learn to react to stress calmly centered?
As students and teachers of Aikido we are called to adopt to a high standard of conduct both in daily life and in a conflict. Yamada Shihan puts it this way in Aikido Complete:
"Uyeshiba discovered the spiritual potential of the martial arts. He believed that the basic principles of the universe are harmony and love and that these can be attained through the martial arts. He believed that a doctrine which does not teach these principles is not a true martial art." and,
"The main purpose of Aikido is to build a strong mind, body and spirit for use in daily life. In addition, however, Aikido also trains its students to live in harmony with themselves and with one another."