Although I agree with most of what you say, I'm of the opinion that an intelligent and practical teacher can learn enough of this stuff to get his foot in the door and then he can alter the practice in his dojo to focus on these skills rigorously for a year or two. With some outside assistance and this focus, I don't think they have to "stop practice"... but they do have to alter it.
..... Gradually, the techniques can evolve back to more complex and realistic Aikido techniques, but always with an eye to doing them completely through with correct power.
Well actually we agree there. I should have said stop practice as it is now done. The exercises done just when training are the slower road still. I also think that getting folks to be able to move with structure is essential. Its where most fall apart and resort to what they know to compensate.
I don't know if we agree or I am understanding you about complex movements though. I just never have bought into complex movements of any kind; Aikido's, Daito ryu's or Koryu jujutsu. It's pretzel logic is only viable when one can capture and draw their energy and even then it offers too many chances. Good grappling I agree with, and "downing a man" (good choice of words BTW) striking him or projecting is a better choice. Or we can opt for everything like MMA.
Even when a certain level of skill is achieved I hate seeing guys get to crazy over themselves in what it does in cooperative play. Broken rythm attacks, feinting and change-ups with full force offer a more intense test. Better still go to a gym or fight club and try it out In a strictly Japanese MA perspective like Aikido's- I'd remain simple and direct both in training and in use. It's why I think adopting these skills in a dojo setting and having slow drills with serious attacks like MMA style would greatly increase the skill level of Aikidoka in using their art. Cases in point would be learning how to stop standup grappling attempts, or takedown attempts with the aikido practioner doing little to make a sucess of it. Then learning to be the agressor. Side benefits being the ability to absorb blows while handling someone. I can see a great deal of benefit to a syllabus with both an actual reduction in complexity and an increase in power at the same time. All down safely and slowely