As for the argument about whether a lighter spring or heavier spring would allow you to lower the LPR pressure, the answer is simple. A heavier spring would allow you to lower the LPR pressure because the only time the ram needs a significant amount of force is when it is extending, because it has to hit the valve hard enough to release enough air. When the ram retracts, there is very little resistence, the only significant resistence is the spring in the ram, and that is very small compared to the force needed to pop open the valve.
As for "cocking", there's no cocking going on, the ram only extends and retracts. You could install a heavier spring, but it would probably be pointless. It would allow you to lower the LPR pressure but you would still have the same amount of force pushing on the hammer and bolt due to the heavier spring, otherwise your velocity would be lower. So, it wouldn't be any gentler on the paint.
It is probably best to leave the spring alone.