Lynn, is that description of yours above (post #13) also provide an accurate depiction of why the shaft does indeed rotate around the sweetspot?
Can it (and/or SHOULD it) be explained through plane angle? That is, the clubshaft must shift to the sweetspot plane going back and once again after impact?
This has always been a slight point of confusion for me. (This may or may not be a clear question, please let me know!)