The most important thing is the layout of the map. Not the props, but the way the entire map connects together, the rooms, etc.
The flashlight is a novel idea, can't say I've seen that somewhere else. I do reccomend using less teleporters though as it's easy for players to get stuck. I also think that you should use less locked rooms and doors. It's not a good idea for players to start out in such a small room and then have to fight over a prop.