I had a very traditional wedding, but some of the stuff was un-traditional. For example, we didn't hire a DJ or a band because we didn't want the "YMCA" or "Macarena" played. We simply went through our CDs and picked songs that meant something to us. I still get compliments on the song list. We also had a SUPER short ceremony, it was only 15 minutes. There were people who missed it because they were running late. You don't have to have a super-traditional wedding. You could even do it at someone's house. Have whatever cake you want. Remember it you and your partner's day, don't let anyone tell you any different.
P.S. I LOVE the idea of a potluck wedding. That is SO cool