the wheel movement by the arms/links relative to the car is always in an arch, raising it can cause camber problems as well as tracking problems sometimes as some cars even have them moving inwards, manufacturers spend quite some money designing the entire thing and then give you a product. Slapping parts on it without thinking makes matters terribly worse.
If you raise or lower a car - you then should know what alignment specs should work as the factory ones are no longer applicable. In your case you can try to find stiffer springs but you would also need heavy duty shock absorbers too to work with those springs.
btw worn out rear shocks can cause the car to be very soft. remove and check their working.