The GS isn't designed for moving material really. It will fill to the top and spill excess over the back. To cut down high spots and fill low ones with what is cut off you can have the blades even with the bottom of the skid shoes. Or to get an aggressive dig/cut drop the blades below the skid shoes.
Putting the rippers down just enough to dig in and break up the top of the packed material with the blades set even with the skid shoes should ensure a good consistent level of material in front of the blades to deposit in low spots.
The weight is fine. Having the rippers is a big benefit that (IMHO) negates the need for the added weight.
Thanks, very helpful