I would say 80%+ of shots over 500y are unethical, and it approaches 100% at 600y barring dead calm air and a sleeping animal.
I'd say it depends on the shooter.
Nope. Even the best shooters in the world are limited in how well they can call wind in the field on a first shot. +-2mph is a reasonable limit for the most skilled long range shooters on earth when shooting in field conditions.
Then consider how far an animal can move from a dead stop during the flight time of a bullet out to 500+ yards. Literally one step is the difference between a heart-lung shot and gut shot.
There is no skill a shooter can have that prevents that. They simply have to get closer.
