Erik, loved your posting. I myself do not practice Aikido, but wanted to comment.
The trick with Aikido is that we have alternatives. We can hurt if it's called for and we can also scale downward (much easier said than done if your attacker has competence) whereas with other arts the options are much less limited.
I was invited to watch an Aikido training in Little Tokyo a week ago, and was really intrigued by the different use of the body dynamic that Aikido has from Shito-Ryu Karate, which I practice. I also have a friend who has been doing Wu Shu for 18 years... and that is very different again.
From the outside looking in, I do think that Aikido offers the martial artist more gentle yet effective alternatives to stop an attacker than other styles I have seen. My style of karate does have some techniques for stopping and not hurting -- but by no means the variety I think Aikido must have, and they are not emphasized. The emphasis is one blow, one attacker down.
Karate was birthed in a nation subjugated by armoured, sword-wielding maniacs from Kyoshu. The assumption was that you never, *never* fight; but if you must fight, Fight. In other words, avoid it to the point where death faces you or a loved one. It needed to end quickly; your opponent was likely to be armed, and there was a good chance you would be facing more than one.
Right now I am studying and watching Aikido (not actually doing it). From only this thread, I think it is clear that Aikidoists are just people too, and as individuals they have different lines in the sand as to where they are willing to hurt or kill someone. But the entire fabric which underlays what I have seen is a very different assumption, which is that when in a fight, do your best to disable them without hurting them.
Why is that? Maybe because, in modern times, we simply are not faced with that terrible, abusive, life-or-death environment of Okinawa hundreds of years ago. Aikido is an art of more modern and civilized times.
I think both approaches have their merits. I pity the Karate-ka who regrets breaking an attackers neck, and with a guilt ridden conscious imagines how he could have done it differently as he sits in a prison cell. I also pity the Aikidoist who tries to throw an assailant to the ground and pin him without hurting him; and instead offers the attacker the second opportunity needed to suddenly rob him of his life.
In the end, all of the above is meaningless banter. What you are fighting for will tell you what you need to do. And from what I have seen, Aikido offers more opportunity to disable your opponent without killing them. I am also worried that an Aikidoist is offering more opportunities for a fellow, trained as I am, to disable them in a less friendly manner.