The Answer is lighter because it will be easyer to use and its not holding you down.
the weight of a defensive lacrosse stick doesnt matter, it just has to be a length of at least 72 inches
Yes, because it is lighter so you have more control over it and you can feel the ball come out better.
The actual stick of the lacrosse stick is called a shaft.
Here is a lacrosse stick charm- http://www.charmfactory.com/lacrosse-stick-charm.htm
It is better to hit with your hands together on your stick. When ever i hit with my shoulder people go flying, but it is easier to get called. so it is safer to hit with your hands.
Lacrosse shorts are very baggy and will stick to your legs when they get wet, they will also get heavy and fall off leaving you butt naked. So no, lacrosse shorts are not good in a pool
a lacrosse stick.
It depends on which stick fits you better. Also about what type of position you play and how experienced you are. Usually at the store they can help you figure out which stick would be better for you.