I think movie contests and actors are very similar. So I would prefer to stick with different movie genres instead - if you want to build a certain actor you will find a fitting movie for sure
Regarding the South Park topics... meh... sorry, but I tried to avoid them because it's not very creative to use South Park characters here. Most parts for them already exist. You could create an interesting scene, but I bet most pictures would be boring.
And another reason is I avoid using South Park too prominently since the official website copied the SP-Studio and made their own version. Of course I still like the show and it's clearly the inspiration for sp-studio.de, but I want to lead the updates and contests in a different direction.