For point #1, what if you could block the location of the source puddle until you want the players to access it (presuming this is the point since the details are a little sketchy here)? Not sure I have any other ideas than stopping the NPCs from wandering.
For point #2, how are you trying to apply the status? Sounds like you want to add some story scripting to make this work. Would need a lot more details to give you specific pointers.
