I've been watching this thread for some months with deep anticipation since about october! I can't wait for the release.
Having made some rather minor missions for racing in Arma 2, I feel your pain. I had created everything for SP and tested in SP and when I took it to MP by simply adding more players it didn't come close to working as expected, and it broke many features...
Charon, you are the Picasso of zombie games!