A few thoughts/questions.
Are so many orgs included that you ended up excluding just a few? A six-org mixer that leaves out two orgs might caused some strife.
How do the girls get bracelets? I'm assuming that the guys have two to give away, one blue and one red. I started envisioning what things the girls will have to do to "earn" a red (hell) bracelet and I had to bleach my brain.
I like the transition from "end of the world" to "H&H", but it seems like a lot of logistical changes during the party.
However, I don't think that you necessarily need a two-leveled structure to pull it off, just two "sides" or rooms. You can create a "partition" by having "Gatekeepers" - some with plastic pitchforks and some with wings (some of your hosts can rotate the job throughout the night). The "middle ground" might even be Purgatory. Tape off a long rectangle and havenothing in it (or put your gatekeepers there). Or if you have a hallways between two rooms, put the gatekeepers/purgatory there.
Some "before" the end of the world ideas:
- At check-in, decorate it like the Pearly Gates or the Gates of Hell (maybe have two sides, just to keep the line flowing).
- "Feast before the famine" area would have food (snacks - spicy chips, Devil Dogs, Angel Food cake...).
- "War" and "Disaster" - have some gladiator movies or disaster films ("Gladiator", "Armageddon", "Twister", even "Ice Age" playing on a tv or projection screen in the background. Once you split, if you have room, have a tv playing "Bruce Almighty" and another playing "Bedazzled".
- "Fountain" of blood (red punch)
- Decorations - pictures of trumpets (do some research on the book of Revelation)
- Have a bunch of clocks around the room; digital works great bc they are really modern (think "24")
- Play music that includes words/themes about time, like "It's the End of the World" by REM, "Tik Tok", "Only the Good Die Young", "Glory Days" (Springsteen), "Forever Young" (Alphaville, the early version), "Bye Bye Bye" (yes it's N'SYNC but the song is funny when you're partying)
- Play some slow songs for slow dancing - "This is the Time", "Time of my Life", "Turn! Turn! Turn!".