Don't read this untill you've finished the game on at least one difficulty.
















As i couldn't completely understand Totality's doc about custom stims, i got round the problem by having 6 custom stims, this eliminated the use of firing arrows into banners/doors or dropping flowerpots from great heights. 

Magic Ritual
So for the magic ritual to get a certain object, each key to trigger an effect is controlled by a seperate stim, this eliminates any cockup by placing the wrong key into the wrong receptor, which happened when I tried to use a single stim to control everything. When a key is placed into its correct receptor, it frobs a big lever in a hidden room, this then frobs a relay trap, that frobs special effects, the sounds were ambienthacked to the special effect. Once all the keys were place a requireall trap was frobbed causing the last receptor to be teleported in, then when the final key was placed, the quest object was teleported in, and the special effects were turned off, and all the receptors were teleported out. If you wanted to find out how this works load the level up into dromed, wireframed view only to see whats going on, move the view to the hidden room near the underground temple. type 'link_draw_on controldevice' into the command line box in dromed, and white lines with arrowheads will be draw between all the controlling objects, you then can trace the route of what will happen when a certain lever is frobbed. (link_draw_off controldevice  will turn the lines off)

Main Quest
The returning of objects to the keeper is also run by custom stims, you could run it by having the AI seeing the returned objects, but there might be a way to lose the AI in that room, so I switched to stims.
Returning the objects to the room itself didn't seam right, but to place them in specific locations in the room seemed to be better, as on expert you have to return 2 objects, just placing one of the objects in the room would have triggered the quest complete and given you all the reward instead of half of it for each object(on expert). So each object returned is a key, and the place to place it is a receptor, on contact with the receptor certain relays and require all traps are frobbed by the receptor, depending on the difficulty level different things happen.

Knockout effect (expert)
On expert you can't knockout or backstab any of the cops, this is controlled by the knockout stim, when you knockout or backstab an enemy the knockout stim is used by the game. If they attack you and are on high alert the slash/bash stim is used. So by making the knockout stim frob a button that only appears on the expert difficulty, which frobs a quest trap var which marks a do not kill quest setting as true, causes the level to end. But if they see you and attack you can either run away and hide, or defend yourself with your sword until they either die or run away.