Dumb question for you guys.
 

Can someone explain to me why lowering the car requires a lower offset to stay flush? What else is changing that causes this? Angle of the wheel? Why is that changing with say 1" lowering springs?

I'm pretty clueless to the inner workings of suspension.

i wouldn't think the offset would need to be different to be just as flush if the car is lowered or not. If anything it might just be compensating for the change in camber on the rears? The negative camber gained from lowering the rears will make it looks more sunk.

camber can change when you lover the car.

I believe that under compression the front suspension gains positive camber. Lowering the car is the same as compressing the suspension relative to the stock height. I think that when the camber goes positive the top of the wheel/tire moves outward. A lower offset will move the tire/wheel in and away from the fender.

Not correct.

Im not sure where that chart is from but they could be calculating the offset required to keep the scrub radius the same as stock.

[ame="http://en.wikipedia.org/wiki/Scrub_radius"]Scrub radius - Wikipedia, the free encyclopedia[/ame]