[Yoda]

Thanks, Yoda!

Forgive me if I'm being a bit thick here , the weight shifts parallel to the target line, right? Put another way, if ones center of gravity were drawing a line during the Slide, that line would be parallel to the target line?

The Slide is parallel to the Plane Line (which normally is also the Target Line, but not always, e.g., Open and Closed Plane Lines). Now, here's the really important part:

The Slide is accomplished while the Right Hip remains Turned. So, it is a Slide (parallel to the Plane Line) with a delayed Turn.

Also, monitor your Foot and Knee Action during the Downstroke. These Components support the Hip Motion and help maintain Balance and a Stationary Head. In other words, no 'saggy-baggy' knees, aka "leg drive" (ugh!) and no exaggerated twisting of the Feet. All this contributes to an On Plane and Centered Arc, the Holy Grail of Golfing Consistency. Study 1-L-#1, #2, #5 and #6.