Answer 1
The protective bubble around the face and head where an attacker cannot get checked?

Answer 2
Only the stick can. If the body falls or moves in the crease, it a crease violation and the goalie is awarded the ball.

Answer 3
1) The best way is to stay off to the side a bit but hang your stick out a far as you
can. The stick becomes the defender instead of your body.

2) Keep feet moving. Flat feet, standing still is a red flag to an official.