Andrew Copp was apparently a pretty good high school QB. Not that he's an overly amazing hockey player.
Crosby is far to small for football, though he has a good core. Might be able to make the CFL, big might, if he dedicated the time early on. Baseball isn't overly hard if you play. I played up to midget AAA and internationally and faced 90+ MPH pitchers and hit them. That really isn't that hard. It's when those pitchers get extremely accurate that it gets much tougher and when they start throwing junk that is also accurate. Not sure if I've ever faced anyone who threw over 100 but I doubt it. Crosby could probably be a great baseball player but even the best player I ever played with, who went to the NCAA and got drafted had serious issues making it past AA ball. And he was bar none the best guy I have ever played with. Making it in the MLB is just ridiculous. You likely have a far better chance of making the NHL as a Canadian athlete then to even make it to AAA ball. He'd probably be a wicked lacrosse player though.