I don't know if that will work in MP, never tried it.
For the elevator, I'm not sure... Maybe move the trigger or something, or use a switch.
I've got an Even BETTER idea, though. Make an old fashioned Q3 elevator (Google some tutorials for them) that goes up when you're on it, and goes down when you get off it. Make it invisible (nodraw) and place it at the bottom of the ladder. So when you step on it, you'll move up the "ladder". You might also be able to make it a little more complex and have it move up a few feet, then slow a little, then move up again, to simulate the effect of the person actually climbing the ladder (just like the ladders in BoaM).
Bassoon, n. A brazen instrument into which a fool blows out his brains.