I'm not sure about Targa cars, but coupes are VERY stiff and just matching the ride heights R-L will get you very close to a 50% cross (FL to RR) or (FR to LR) as jwmelvin has said.
You can achieve a 50% cross and have all of your ride heights goofed up R-L with 1" difference R-L or more. The goal is to get to 50% cross while having the spring perches as close as the same R-L (preferably well within 0.25" from eachother).
Front to Rear weight distribution is dictated by your car. The NSX is inherently a 40/60 distribution and you won't change that unless you add or remove weight in the car. If you take a stock car and add an aluminum front bumper, carbon hood, lithium battery, 02 headlights, 02 abs, etc... its possible to get 38/42 or more distribution. Likewise, leave the front alone, carbon rear decklid and wing, aluminum rear bumper, no rear hatch, etc... its possible to get 42/58 or more distribuiton. Raising the front or the rear will do nothing to transfer static weight distribution to the front or the rear. Same thing with right to left. The right to left balance is dictated by your car and whats in it, but the NSX is pretty even L-R. At the end of the day 40/60 is arguably better than 50/50.