It'd be a good idea to have a weekly (or fortnightly) meetup to play on the unused maps. I'll play every now then as well.
Just a heads up, I don't think the codes will work at all if you do party invite or join your friends game (who is playing on the unused maps of course). I could be wrong though.
There is a way to apply codes to your Wii without using the Homebrew channel. And it is 100% safe (unless you used codes from unknown people).
But really, applying codes without the Homebrew channel is just as safe as applying codes with the Homebrew channel, only difference is, Homebrew channel is quicker and easier.
The Homebrew channel is just an ordinary channel, it CAN'T harm your Wii at ALL. Just having it on the Wii menu is completely harmless. The things Homebrew channel can boot up and install are what can harm your Wii (leaving it utterly useless).
I'm not going to write a tut on how to apply codes without homebrew channel, because really, there are MANY out there.
I watched a huge video that Dane posted with a lot of the unreleased maps on it... It was definitely awesome and as I mentioned to Dane, the timing from the start of the game till when you run into your opponents is savage! Sometimes only a few seconds! --- The only time I was wrong, was when I thought I was wrong. http://www.youtube.com/watch?v=XKYZSuKEq3U [RS]Enzo