Thank you for the descriptive reply. I think I see what you mean in the last paragraph about the feeling of the shoulders on plan and the club underneath it. I realize how so many things can go wrong and that getting into a correct set up works wonders to eliminate many of the problems.
The right forearm action is fantastic when I get it right. Sometimes it is a total mystery to me. I believe focusing on the pivot may indeed eliminate some of my thoughts/questions about the use of the left arm.