1) Sorry, the disc is only going to be free for people who bought the PC version from the website. We just don't have any way to do that for Wii purchasers.
2) We haven't decided on extras yet. We'll be meeting to plan this out in more detail soon.
3) $34.95, since it comes with the PC season set.
4) Not sure yet, sorry! It partly depends on the answer to #2