Greg,
Apart from the slight twist of C13 on the big nut C20, all the parts are rotating together with the mainshaft. Loctite might be a good lubricant for the race!
The rubbing takes place at the other end, and might be needed to stop the parts so that first might be engaged quietly.
Too much travel can cause a spring to become coilbound in my twin. This can tilt the plate with the standard set-up....so more slack is better with the proviso that when stinking hot in traffic there is sufficient movement left.
Tatty