Here's the scoop:
Keystone is FULL of pros. If a skier is not injured, he's skiing at keystone. Obviously, this is awesome cuz you get so see them and ride in the same park as them, but it can also be intimidating. Don't let their presence scare you. They're just out there chillin like you. They don't care if you fall or fail or anything. They're all super nice.
There are three parks and they have features ranging from absolute beginner to epicly large. And literally everything in between.
Just have fun. It's a super fun park.