Polo Rules

So can someone clarify the following for me.
2 players attacking, is the player not in ball possession aloud to screen a defender to protect the ball carrier? Does it matter if the defender is stationary or not?

Can I mallet fuck stationary players, as long as It's not a slash?

Will polo ever be fun again?

You are always allowed to screen, in any situation. Just expect contact from the other player if you do.

What's mallet fuck? You can't hack, but you can hook (as has been the rule for years, that wasn't changed)