Taking the belt off doesn't really help anything. It just makes it harder to drive 0-10mph. If you actually remove the PS pump, you will have to loop the line (after you drain the fluid). This is still not the same as a manual rack.
Your best bet is to find out if the car was ever offered with just a manual rack. If so, get one from Mavel and install it. I am about to convert my RX7 to a Mavel rack also. Much better road feel, plus about 30lbs less weight over the front wheels.