Yes you are right on many things but those guys are the very top, they have trained for years and years and have conditioned themselves for this. In track and field/cross country skiing etc. they have 100 lbs people with heart rates in 200's (during the event) and then you have 300-400 lbs guys pulling a truck with heart rates of 150. So many of these guys are def. built and conditioned for this. As for steroids, i know for a fact that many PL's and strongmen use a lot less than the Olympia line up + they don't use many of the exotics that really take their toll. As for the most dangerous drug usage, i'm fairly sure it's by endurance athletes that try to pass the test's by using very weird compounds AND the very top bodybuilders.
WSM looks "worse" than it is.