Got a few questions rattling around in my head and was wondering if anyone can help me out?

This is what i've figured out, i think...........

Can reduce/eliminate bumpsteer in a zed by repositioning the lower control mounting point on the crossmember, this effectively raises the roll-centre of the car, this is with the stock ride height of the Zed,

Now you lower the car, say 2", you will also lower the roll centre of the car,

DOES this mean that the above mentioned modification to remove/eliminate the bumpsteer will become ineffective?

As far as I know, the "bumpsteer modification that you describe is done to minimize (or maybe eliminate) the negitive effects of lowering the car. I haven't heard of anyone doing it to a car that hasn't been lowered.