I always thought of it the other way around - that aikido is a particular system of principles and techniques to get and keep kuzushi, and that there are other systems that are similar in some ways and different in others. Once you've got really good kuzushi it seems like that's the point where you're basically finished the technique most of the time? If you keep doing more after it's basically henka waza, isn't it?
I think this is a good illustration of a mis-communication on this topic. I mean, its completely wrong to thing about kuzushi like this, but clearly you and I are imagining two different approaches (mine being right and yours being wrong). Just kidding.
Seriously, technically, I think you are correct. Ultimately, If I move with aiki, my partner will always be unable to affect me. I am yet undetermined if that is "kuzushi," or simply the inability to affect me. Or, if they are the same thing. But. In the context of this thread, I advocate using a basic method of understanding kuzushi, then learning aiki to achieve kuzushi, then learning waza from kuzushi. There are instructors who advocate first understanding aiki, then achieving kuzushi through aiki. Without hijacking the thread, for the moment I am adverse to this teaching order because:
1. Aiki is the devils' work
2. it is far easier to screw up aiki training than it is kuzushi training
I am open to changing my teaching style once we get a bead on the system, right now I do not think there are enough aiki people out there to roll a teaching methodology and keep the oversight intact to prevent us from screwing it up. The aiki training I have thus far experienced is difficult, frustrating and largely met with low success... While definitely the goal of my training, I concede that I first need to figure out what the f%#k is going on with my body and my partner's body. For me, that means I am starting to treat this [remedial] education as pre-aikido. Then we have our aiki training. Then we have our aiki do training.