That's absurd. The mechanics of gravity, parachutes and jumping out of planes is well understood. Plenty of people have fallen from heights without parachutes, and we know what happens to them and why (acceleration of gravity and the force impact on their bodies). We also know how parachutes, used properly, mostly prevent that sort of harm (slow people down enough to prevent excess force when impacting the ground). There's nothing superstitious about it.
Yes, and in a similar manner we can know quite a lot about how people would behave in situations like the one in Milgram's experiment even if we won't ever do an exact replication.
Yes, BUT in similar situations people behave very differently than the ones in Milgram's experiment. This is the whole point of it being not replicable.
That this remains true is due to a) no one being allowed to repeat Milgram's experiment exactly and b) more general scientific funding bodies not allocating money for pure replications.
