So when an opponent grabs my wrist, I enter while turning (that's the tenkan) and I must manifest this basic kokyu force of Aikido into a direction that suitably begins the lead-into-technique. The lead into the technique of kote gaeshi involves you forming the kokyu force into one direction, up, then over (every bit of the movement is powered by kokyu force). It often looks like a sudden, straight technique but if you analyze the directional changes the kokyu forces go through (if you did it correctly), those forces make a circle. You may have included another circle horizontally (here's your beloved centrifugal force ), but the leading force you use to effect putting your partner into a centrifugal arc is also part of the kokyu power you must manifest throughout the technique.
I can follow this much. What you seem to call kokyu here is what I feel as a mix of Alignment, weight, balance, er.. the "apparent power" from Uke pushing against the ground through me and back through .. How does this relate to breath and intention is what I'd like to ask you, because that is what kokyu implies to me as well.
I guess I can understand Tenkan as being indepent of the application of force; since sometimes you can enter and turn behind and drop uke without the "apparent power" but by "removing the structural support" . I just wish I could get the labels right so I understood what other people are talking about.