jonathan, after long and deep contemplation, actually, only a few seconds between the time i poured the coffee into my cream and sugar. i'll toss a few things out for laugh.
1. it looked as though your power was trap between uke's wrist and elbow. it needs to reach through uke. when Ikeda sensei doing the stuffs, uke felt as though he reached inside uke, grabbed the spine, and move it around. the outward appearances of the techniques are the results, not the cause. thus, the meaning of internal.
2. view your arms and uke's arm as one arm, your arm. the connection is your elbow and uke's shoulder is your hand. so try this, reach out with your hand and grab uke's shoulder, then try to move him around with your body, i.e. lock your arm in place.
years ago i went to a seminar taught by Hooker sensei. he discussed the different between learning and training. i'll paraphrase. learning is when two person helping each other to accomplish a task to gain maximum knowledge. training is taking off the gloves and test what you have learned; there will bruises and blood letting.
so the question i would ask you is, are you learning or are you training? they have two different mental attitudes. what Ikeda sensei shown was learning mode.
systema learning methodology that you might want to consider. at the beginning stage, you use the least amount of force and doing everything at snail pace. this is to NOT imprint tension in your body. so repeat after me, "tension is the mind killer. i must not tense. i will let it pass through me."
after a time, then increase the power and/or speed, very slowly. also, your uke should provide the power, either push or pull. just stand there and grab provide no power for you to manipulate; thus, you have to supply your own power into the equation. thus, you were doing things to uke.
so the power equation should be
uke's power + your power = 100%
that means if uke's provide 70% of power, then you provide 30%. "four ounces pushes a thousand pounds", right?
now, back to my requirements discussion with Marc. the last two is ura whereas the first two, omote.