Overall, great post. As far ukemi is concerned, I agree that too many are too quick to jump into the dive. I see this at many seminars mostly from young yudansha who just love throwing their bodies around the mat - the older ones seem to have learned to not do that though
However, I still think ukemi has a roll in training. Granted, newbies are not that prone to take a fall, but that should not be viewed as resistance to a technique, just simply an indication of not knowing how to protect themselves. In this case if nage turns up the technique, the newbie gets hurt. I think ukemi teaching needs to stay in the basic training, but I also think there needs to be more application of resistance by uke based on the appropriate skill levels of both nage and uke - this should create an environment where both nage and uke can ramp things up in a somewhat controlled and safe pace.
Most everyone, I think, understands the silliness that is the huge "breakfall" or the "air time". It's a cooperative endeavor, for the most part.
And most everyone, I think, understands the necessity of knowing how to roll, fall, etc. Just a quick glance at other martial arts shows that there is some amount of training on rolling and falling.
I'm going beyond all that. I'm going to the heart of Modern Aikido's training paradigm of using the ukemi model. In a fashion, training includes not going against the force by using the body to move certain ways and to then train the body to roll out of situations. This training ingrains specific reactions in people that are, at the heart, opposite good martial training.
Do we really think Ueshiba was rolling/falling when he was fighting, sparring, or being tested by other budo men? IMO, Ueshiba's version of ukemi was to manage the forces/energy of an attack internally such that the option of roll or fall was never there.
If any of us are looking to the future of aikido and looking to aiki, I think we'll have to take a long, hard look at every aspect of Modern Aikido training and to sit aside what we "know" so that we can look at it from a fresh perspective. And maybe some are already doing that.