Just as in Basketball, a pick is when a defensive player is cut off from the person she/he is defending, usually when that person runs so close to another player that the defender is "picked off." Unlike basketball, it is illegal, mainly because it can be dangerous when players are running at top speed. If a pick is called, play stops and the defender is allowed to catch up. If the offensive player that did the picking catches the disc, they have to send it back to the thrower and the defender is allowed to catch up.
Ultimate Frisbee is the correct way to spell it.
Frisbee golf
Ultimate Frisbee is most popular in New Zealand and the United States.
No, you do not have to win by two in Ultimate Frisbee, just first to 13 or whatever you are playing to.
I wouldn't say 'national championship' but the professional sport of frisbee is 'ultimate frisbee'.
Ovbiously
Screens, aka picks, are illegal. If a pick is called, play is stopped and the previous possession is redone as if nothing happened.
Ultimate Frisbee is the 'football-esque' version of frisbee, but there is also disk golf.
The handler in Ultimate Frisbee is responsible for throwing the frisbee to another player, called the cutter. The handler is an offensive position much like a quarterback in football.
Ultimate Frisbee Ultimate Fighting Championships
It is typically seven versus seven in a typical game of Ultimate Frisbee.
No, no physical contact is allowed in Ultimate Frisbee. That would be considered a foul and the play would reset.