Been cogitating on this.
First, my initial point was just that if one doesn't show one's partner where he's open, one is doing his partner no favors. Some of those openings may involve killing techniques. Doesn't matter, from this point of view.
But where I really get hung up is when people start clutching their pearls over the idea that somebody might actually get hurt from an aikido technique. Guys! And gals! This is a martial art! It's about hurting people! Yes, aikido always offers a way out, so that hurt is a choice... but it's not always the receiver's choice. A boneheaded attacker can pretty much always get themselves hurt. And you'd have to be a better aikidoka than O-Sensei to never hurt your attacker. And in the real world, you can't have any confidence of defending yourself without getting hurt and without hurting your attacker.
If you avoid this truth, as I think you do if you cling to a view of aikido that's all niceness and bunny rabbits, I don't see it as noble. I see it as hiding your head in the sand. If you've taken on a martial art, IMHO, you've taken on the challenge of tuning yourself into the best weapon you can be. Yeah, for most of us the macho wet dream of beating down the five thugs mugging the helpless old lady isn't ever going to be on the table--and yeah, if we use our training well, most conflicts should never get to the point of violence anyway--but we are training to be able to maintain control in difficult situations. Our strength may be a gift to the world if we use it wisely. Our weakness can never be.
The paradox is, if we follow the path faithfully, we discover that we control a situation by not trying to manipulate it. We discover we can use connection rather than force. We discover that the most irresistible power is the softest.
But there are no short cuts. If you're following a martial way, you have to follow it. Otherwise you just have mush.
I hope you don't mind me coming in here but the view you express on harming and this being a martial art I would like to offer a perspective on. It may be only mine, it is what I teach, but I doubt I am the only one with this view.
In my view O'Sensei after his realization and presenting his new way of doing things subtly altered the techniques. I believe most peolple agree with this point.
Now personally, along with what I was taught, that equalled techniques designed not to harm. The path and discipline thereafter led to the discipline (martial) of doing such with definite application.
Therefore I can do a definite shihonage in such a way that the uke cannot be harmed, it's not a matter of he has to do a certain breakfall in order to save himself from harm. In my view the subtleties need to be learned number one knowing the reason and the funny thing is when you learn them this way you find they are inescapable by the uke.
So some may find that hard to believe that the harmless technique is not only more powerful but inescapable in comparison to the ways they used to be done where the aims of those jutsus were to harm or dislocate or maim.