1 rooster per 10-15 hens is all you need for fertile eggs in a flock. Only reason to have more than that is if you have pairs or trios ect in a pure bred set up. Even then, people often keep the rooster(s) in a rooster pen so the one or two hens in with him do not get too much attention. Your scenario of so many roosters that the hens can't eat or rest (and die) is very sad to contemplate.
Feathers broken off of hens from rooster attention will molt out when the chicken would normally molt- this may be a few weeks or 6 months or longer. This feather loss is in general a cosmetic problem only. Unless sunburn in your area is an issue. They will need free choice to good quality ration for recovery. Layer pellet or the higher flock raiser type + oyster shell.