Yes, they spin, and that's where the fun begins. The two 9-blade fans are positioned lower and spin slightly faster than the two 6-blade fans. This is important to remember. Adjacent fans spin in opposite directions.

Gametypes: I've only fixed the spawns for Oddball. Entity refused to view the BSP, making all further spawn edits a prohibitive hassle. This map was built almost entirely by employing my hard-fought knowledge of Cartesian and polar/spherical coordinate systems, and a lot of FTP-ing. I'd love to add KOTH and CTF, but that's a crapload of coordinates to calculate and enter by hand. I might do it if enough people pester me though. As it stands, this would be a great map for slayer, oddball, juggernaut, and zombies.
Weapons: There are no weapons or ammo on the map. I didn't want to clutter the space or the few stable XY surfaces, or manually edit all the itmc spawns. Instead, the less crappy guns (by my judgment) have been quasi-infinite ammo-tized. This may seem cheesy, but trust me, you've really got your act together if you can unload ten clips or kill two other people before you die on this map. It plays very quickly. Short range weapons work best.
Due to a deliberate quirk in the Halo physics, the Master Chief maintains his yaw, pitch and roll even while he should be rotating out of them. I presume this is so that you don't feel like your reticle has been hijacked by Isaac Newton. Anyway, what this means is that you automatically counter-rotate to maintain your YPR, and keeping the reticle on a fixed point in space is easy. This makes scopes very cheap and unbalanced, so they've been removed. Additionally, magnum bullets do a bit more damage. The one clip wax factor is in effect, as it should be. Bungie came so close to not botching the magnum.
Here are some weapon combinations I suggest for this map. Set them in your quick options or game type. It's what everyone does anyway, right?
battle rifle + magnum
carbine + magnum
carbine only
magnum + magnum
Shotguns / swords (lunge melee at your own risk)
ROCKETS
In addition to the above guns, the plasma pistol and plasma rifle have also been infinite ammo-tized. Nades are worthless here unless you're really good at sticking people with plasmas, while both you and your target are on counter-rotating merry-go-rounds. In that case, you might wish you had them. TDB.
Gameplay tips: Make a custom game type where the suicide respawn time penalty is off and lives are unlimited, because you are going to die die die on this map. Even once you've figured out the reference frames and have a feel for the funky Halo physics, you will be taking many a flying leap. Everything moves except the claw below the center carousel, and if you end up on the claw, it means you have eaten your last can of beans this side of Oblivion.
Still, it's great fun. Just expect that the suicide tolls will be higher than usual.
Physics time

Huh?
Just play the thing.
The other big clue is that you want to jump such that something will be under you when you land. I know it sounds obvious, but it means you may have to jump toward what is currently a gaping hole in space, reckoning beforehand that a fan blade will spin underneath you at the proper moment.
By design, it is not possible to jump from a lower fan to the adjacent higher fan. The height differential and orientation of the blades make it impossible, so stop trying.

Try it. You will die a lot, then you'll start to figure it out, and then you'll die some more. Don't get frustrated.
Credits:
Entity 1.6. It's not perfect, but for everything it can do, you can't beat the price.
UndeadGhoul for his tutorial on active scenery.
Headshotmasta, for graciously supplying the sky/ambience/fog, and many top shelf mods in general.
NOTE: THERE IS NO SKIN. I HAVE NO INTEREST IN SKINNING.
I AM NOT GOING TO SKIN.
I AM NOT GOING TO SKIN.
I AM NOT GOING TO SKIN.
Download from filefront, because the halomods server didn't like my patch. I'll try again later.