I'm half asleep (4 hours sleep - I should really get something to eat and go back to bed) and frustrated with my game (can't get the new TS4 cheat to work) so bare with me here.
Please don't overthink this. So many people overthink everything that has to do with SimsFilmFest.
The only requirements for things are list of items listed in the rules, and you've got quite a bit of time to do those. Outside of that you can do as little or as much as you want to. You don't have to create any huge story for your band unless you want to. If you're feeling extra creative you can come up with 100 more promo items and submit them if you want.
Someone ( @KevinL5275 I think) mentioned that they don't have the photo or Photoshop skills to enter. The first year we did this I didn't either and learned as I went and I really can't do more than the basics. It's really all you need. I can credit entering BotB for forcing me how to do learn to use Photoshop and take better pictures. Please don't let lack of skills stop you. Someone on staff is always willing to help out (we have at least one person on staff that lives for doing graphic stuff and helping people learn to do graphic stuff). I'll even help. :) We really want this to be open to everyone.
I had another thought and I probably wasn't kind to it, because I lost it. Oh...one entry per person. This might change depending on how popular the thing turns out to be.