I have cut all the ballcups on my shocks. It may not be necessary for asphalt, but it's sometimes impossible to get the car low enough on carpet without cutting.
It's quite important to check that your springs are the same L/R. If you have lot of them laying around, you may have them from different batches and they are different. Just yesterday I opened some bags of new blue springs and compared them to some of my old ones (really old)... the new ones were not only wound the other way around, they were also a bit softer and 2mm shorter. A good way to test if the springs are at fault is to change them L<->R and see if things change. Checking tweak after the change is probably a good idea too.
Weight distribution: with GP3300 my standard car was off by <100 grams. There's no way I can shave that much weight from the car without going bankrupt (it's a bit overweight as it is), so I chose to move one battery (~65 grams) to the other side. Works well and at the same time makes the total length of wires shorter