as for the challenges, it depends on what you want, there are two challenges per year with prizes and two contests with prizes, anyone can enter all four.

but if you win a prize, for example, the Redemption DVD, you can't win the prize for any of the other challenges and contests, (like the Red and Blue Filmography) this gives everyone a chance at a prize each year.

There is more of a chance to win the Redemption DVD, as there are fewer entries for challenges than for contests, but, if you really want the Red and Blue DVD's you might want to hold out for them?