Moving the tires doesn't change a thing with respect to calculating the wheel rate of the bar. The effective length of the lever is controlled by the LCA, from the pivot to the lower ball joint.
I don't understand your reasoning. If you put a big wide offset on the thing, the car will sag lower. The spring rate will effectively decrease. "Saying" that you are figuring it to the ball joint may make "the math" happy, but the real world effect is it will be softer
What you are doing effectively, is putting a pipe extension (wheel offset) on the end of your breaker bar (LCA)
