Do you need the code scene to be a scene? If not, consider just making it on a different layer and when they hit the book or w/e have the camera in that layer tween to the code paper and when they hit escape you can move the camera off it. Also i think you can still pause the game doing it like that, I’m always seeing people in here changing the timescale in their events.
The door thing is supereasy and there are so many ways you can do it. In fact there was a post a few days ago
in which i offered a simple and rather brilliant solution (hehe) and the other guy had a good solution too. So he has his events up you can look at.
The gun thing what are your events for?