Well, sometimes the code just writes itself, nearly. I have made good progress, and now all collectibles (potions, etc), npc’s and containers (like chests) all come from area data, which can easily be manipulated, and will be easy to create from editor mode of the game also.
There is is also basic alertbox that can be [...]

You see a chest on the ground. You carefully approach it, and since there apparently are no hidden traps or lurking monsters, you decide to open the chest. Then…