You'd have to change the pivot points of the suspension arms - so on 95% of all production cars there is no way to change the toe change over suspension travel on the rear axle - the height has to be adjusted so the arms are in an optimal position to get useful toe and camber changes over suspension travel. Just lowering the car isn't always better, especially because the roll center often changes to a degree that's not helping the handling.
the rear suspension on the galants is intentionally built to give more toe-in on compressed suspension, so you get more slip angle when cornering, thus making the rear more responsive. The rear steering further increases the slip angle.
On the mcpherson struts at the front you could use height adjustable steering rod ends (normal uniball joints + long, high-strength bolts with washers is the standard motorsport way...) and measure/adjust the toe-curve over suspension travel with an laser-leveler strapped to the rim and pointing forward and a big piece of paper in front of it. it's easier if you remove the spring for this precedure, so you can easily change the wheel height without raising/lowering the whole car and thus the pivot points. (don't forget to measure the height of the still standing car)
as you already removed the springs you can also record the camber changes over suspension travel (pointing the laser downward) - the more you know about what your suspension does when driving, the better you can improve it...
From what I measured/calculated so far at my car, the VR4 suspension definately needs some height and suspension travel for optimum performance - lowering the car too much will have the roll centres move too far down, making the car "wobbly" around the longitudal axis and also making the steering-trapezoid behave weird because the steering rods are pointing upwards (they should point slightly downward for best steering response/feel)
I'd say the optimum lowering is only around ~2cm on the front and ~3cm at the rear (the rear could be lowered a bit more than the front, especially to help reduce the change of center of mass when braking). Yes, this might not look as good as all the extreme-drop-bling-bling-suspensions which lower the front just above the ground, but it handles and behaves much better...