Moving ball joint
I don't know if I missed this, but moving the ballpoint out of the arm won't fix roll centers. It just looks that way. The pivot point at the ball joint is actually where the roll change happens. If you draw a line through the center of the ball joint, and the pivot of the control arm that's your angle. The arm will look level, but the center didn't move at all. A modified spindle is an option. A fabricator for the VW MK5 GTI makes one. It addresses all the issues. It fixes bump steer too. With that approach you can use stock ball joints. No squeaks, or greasing. Less vibration. I don't see why it couldn't be done for our cars.