Also, unbalncing is done by maintaining strong lock on attacker arm elbow from the moment of the contact all time down + keeping him always in mouvent.
This strong lock serves as a connection to uke center so in the moment of throwing it is enough that nage moves his center across a center of uke and throw happens without doing any waving with the arms.
I can clearly see that the arm lock makes this work, particularly in the faster version. Bill Gleason has an excellent quote about aikido that relies on arm locks to make it work.
Mike, it is really hard to discuss technique online like this. Hopefully one day we will be able to train together to show each other what we mean.
For now, I agree with Janet.