you do not have to specifically train the rotator cuffs. I've been benching over 400+ (550+ now) for the past 15 years without a single injury. if done with proper form and progression there is no reason for any injury in this sport.
one of the biggest reasons for injury in the sport that's associated with heavy lifting is person not taking enough time off to give the body a complete break. regardless if a person is training natural or using AS.
I've regulary taken 2-3 months off a year since I started training in '82 and have not had one single injury related to weight training, even when PL and I've got my 2000+ lbs @ 229 lbs.
I don't have the abstracts but there are several recent studies on the topic of taking extendend breaks from weight training and the benefits.