But all said and done unless a person understands the change O'Sensei made as to purpose then they will never learn his Aikido and therefore the practice of the exercises he gave will not be understood properly and the why will not be seen.
Your post was good I thought by the way. I just offer my view.
I thought Jon's post was good too as it raises interesting questions that make us think about why and how we do what we do.
On learning O Sensei's Aikido, I'm not sure that will happen for any of us. For instance, both you and I use Ki development exercises to inform us of how to aproach the practice of aikido. These exercises as you know were not O Sensei's, they were developed to help aikidoka train towards what one talented student/teacher felt was the 'stuff' that O Sensei had, but wasn't teaching in an explicit way. So as much as we get from the deep study of these exercises, they are there to point us in the right direction, not to be the destination.
My guess is that by relentlessly pursuing the essence of what lies inside these exercises (and I don't know about you, but the more I delve the more I see), we will come to our own conclusion of what aikido is for us as an individual.
If we can discover where the moon actually is then and only then can we start pointing at it