Chloraflora
NOLU
I think we can agree that they are two of the most difficult positions, but I still think catching is more difficult, probably from experience. Respect to keepers though.
Catchers have to know their pitching staff and know scouting reports for the opposing batters to call the game. They have to frame 80-100MPH pitches to make balls look like strikes, block pitches in the dirt, and throw out base stealers. Then on top of all that, they have to get up there and hit at least ~0.250, which is in fact the hardest thing to do in sports.
No, it's not. Unless you mean in the four main North American sports, which even this is still debatable.