[rwh]

Five minutes later Steve had me doing start-up swivel drills. He said, "Fan it, Fan it as hard as you can at startup, you can't fan it enough". Note to the reader, this is clubface fanning while tracing a straight planeline, not taking it inside at startup.

Great post and an important point that you've made. The swivel has nothing to do with arm movement other than a rotational movement of the forearms. A complete swivel can be made that moves the clubshaft parallel to the target line and parallel to the ground and opens the clubface 90° without ever moving the arms from their address position.