i have a new 82nd airborne rated at 60 to 70 pounds i hurt my shoulder and have the poundage backed off to about 54 pounds will it hurt to shoot it at that poundage

the closer to the top end the better,less play in the parts

does that mean it is unsafe to shoot at 54 pounds

does that mean it is unsafe to shoot at 54 pounds

As long as the limb bolts are threaded all the way through the "nut" in the riser, you'll be fine. Granted, there will be more play between the limbs and the riser, but I can't see how it would be unsafe.
I have my wife's 60lb. Ally backed off to 45 lbs., there's no problem and it still shoots good.