A girl recently ran all 5 consecutive days of Hell of a Hill marathons (very hard off road event) day 1 was her first marathon attempt, so three is a challenge but not so big as to be impossible just don't go flat out
Allowing drugs is a stupid idea. It's not a level playing field at all. Clean runners would be penalised. Why would you see that as desirable?
I wouldn't see it as desirable, but I would say leave the few elites to do it, and let them worry about who is clean, then the money spent administrating pointless drug testing (clearly it doesn't work) could be spent where most people actually care about, at grass roots
Also bear in mind that most of this stuff is at the very least unhealthy if taken for long periods, some is downright dangerous to life if taken without proper medical supervision.
Same applies to alcohol, Heroin, coke etc it's all a choice, it all seems a big fuss when athletics is a mass participation sport and really there are only a few elites who will benefit from or ruin it.