You can measure them but you'll need a drive on hoist to get under the car to get the measurements with the wheels on the ground. Get a Faro arm and put it on a drive on hoist to measure suspension points to determine roll centers (this would be an expensive option but you'll have a sweet toy). Or if you don't need to be that exact you could just do some measurements with a tape to find the points, draw it out, and get the roll centers. You can find the center of gravity with corner scales. Check corner weights with car on flat ground. Then do it with the car tilted, going to need the drive n hoist again, leave one end of the car on the ground and raise the other end slightly with the hoist. Measure the angle of tilt, see what the weights are when tilted, you can find the CG from there.
But I agree that none of this is going to help you find the optimal tire pressure.