I hate to be a dose of cold water on this but I'm going to rant a bit here.
There are a few questions you should always ask yourself when you design traps?
What is the purpose of this trap? Why was it created? How was it created? How can it be defeated? Why can you defeat it?
A trap is not supposed to be a slow down or "speed bump" on the way to a treasure. Traps are meant to be a deterent and a warning for tomb raiders (since you used the terminology, I'll stick with it). They should be deadly, period. That being said, a rotating hallway, is not.
How does this hallway rotate? What is it built out of? The amount of money for a trap of this size to be constructed and not be deadly is a waste of gold. You are spending literally hundreds of thousands of gold pieces to create a nuisance - I would just have a round room with no doors and no way out but the way in- cheap, easy and ultimately just a nuisance.
If you have this rotating hallway, there must be moving parts somewhere - any thief or dwarf worth thier genes should be able to figure it out and deafeat it. - Problem solved -
All that money spent and a pebble in the grears is all its going to take to take it down. (conjecture)
Traps should be easier to spring and final (to an extent) when you do. The classic large traps are based on ones found in history while raiding the Egyptian tombs of the phaoroh's. Sand traps, block traps, pits, spikes, poisons - all cheap and easy to incorporate into a design without infating the budget much. False rooms, dead ends and entire levels of nothing leading to deadly traps are also fairly cheap and not outside the realms of possibility. Magic does add a new element so some things not available to we "normals" would definitely work (Your anti-magic field for instance is a GREAT way to limit escape and is easy enough to pay for in the grand scheme of things). Should there be ways out of traps - only on technicalities, no trap should have the "golden lever" that defeats it. But in the example of the sand room - a good strength check (getting harder as time flies) should be able to wedge open a door (or drop stone) so that people can attempt an exit. It isn't built in, but there is the possibility of escape.
An easy, fairly cheap trick/trap I use is a magic-based fake out the party trap. Please follow along.
DM: As you file down the hall you come to a 10' square pit in the ground, it looks like its deep and you can just make out the faint shapes of rusty spikes pointing menacingly up from the bottom toward you.
The stupid player (there is always one that tries this and I'm not sure why?): 10'? I jump across.
DM: Okay, make a long jump roll
Player: 19 - I'm so over this...
DM: Mid-way across the pit your body suddenly jerks straight up and into the ceiling. The rest of you hear a sickening thud and the sound of flesh rending. You may want to roll up another character....
Other players: We
Detect Magic
DM: Now that you mention it....
The trap is actually a pit dug with spikes, an easily detected trap unless you are blind, the pit is deep enough however that no one can actually see the bottom of the pit, just the faint points of the rusty spikes (rusty from dis-use). Above the pit (becuase no one is going to check above is an
Illusory Wall hiding ANOTHER pit with spikes in the ceiling (15' deep) and a
Reverse Gravity spell cast in the area above the pit. Person jumps, flies, etc, over the pit and soon they are on a one way trip to skewer city. Simple, deadly, cheap. And, even if they dispel the area of effect, they still have to get across that deep pit below. (Dual effect is much better than one shot.) The trap cannot be thwarted through rolls, but must be thwarted through role-playing, so it is much more engaging and ultimately, memorable.
And one other thing, traps should never include monsters or venomous animals - they need
food and will eventually starve meaning the characters will walk into a room full of bones of guardian monsters unless this trap was just built. (Why do you think mindless, non-blood or flesh craving undead are so popular as tomb guardians. /ie mummies, skeletons, etc/)
While the rotating hall sounds great - it straight out of Hollywood and frankly is just not feasible or deadly. Go smaller but better designed, heck, steal my pit idea, I don't mind, really. I'm just sick of seeing the "Gold room" traps and the "slide of death" that are just plain stupid...
My two coppers, hope this helps.