You ask some complex questions here. I wonder if you are confusing centre of gravity and polar momentum (mass centred about the axis of rotation)?
The question about the sway bar depends on what you are trying to achieve. A sway bar is a way to alter weight transfer and roll resistance during a turn indepedent of the spring rate. You can increase roll resistance and potentially weight transfer by a sway bar without having to increase the spring rate at the wheel. This may be beneficial on a rough track. The wheel spring rate is still low enough to allow sufficient wheel travel and keep the tire in contact with the surface and yet the chassis resists roll during the turn because of the sway bar linking one side of the chassis to the other. That why Lincolns and Cadillac have sway bars front and rear. They can then run light springs, yet still have acceptable handling. But none of this affect the centre of gravity. It just reacts like its lower, because the chassis resists leaning during the turn. But weight transfers nevertheless.