i have a bad shoulder as well and it hurts like a mother after shoulder or chest workout, im pretty sure i need surgery however i put it off becaus ei dont have medical at the moment, instead i do rotator cuff exercises before both chest and shoulders and i try to stick with a weight i can hit atleat 3-4 times, however when feeling good i like to max out on bench every now and then
O.k. A TINY bit of advice.
If you have an injured shoulder.
#1 - going to a 3-4 rep range on pressing movements is not smart. Stick to 8-15 and a more moderate weight.
perhaps your joint will heal itself if you stop messing with it.
#2 - no maxing out.... unless you are 17 and in high school.
Then... Max away.
#3 - QUIT FLAT BENCHING. There are alternatives. Heavy incline, heavy low incline dbell flies (not presses).
Flat bench is not the only way to build chest mass...