I don’t have an answer, however I am interested and did use high speed imaging for problem solving high speed process errors in a previous employment.
I understand that you are not going to get very far without a reliable datum’s and reliable measurement systems.
It might help to understand what aspects you were trying to quantify. Shaft rotation is probably the easiest to understand as it would be represented as a +/- angle of rotation from a zero point, however what measurement aspects of the “club face” and “grip” were you looking to understand? For example, grip height at point of impact? Horizontal and vertical angle (orientation) of the face at point of impact with the ball? Etc.
With a little more information, you may find some covers will be able to throw some ideas your way.