Grimrock

I can't see any other posts on the subject, but I want to create events to occur when wall text is read/clicked. I don't know if this is possible.

I'd also like to create self-destructing notes. I can't seem to figure this out either

Not possible, to my knowledge. But would be nice.

If your wall text is positioned so as that the player will be sure to read it as soon as he is standing infront of it, then you might be able to use a hidden pressure plate that activates whatever it is you want to happen as the player steps off the pressure plate. Thus happening after the message is read. Not really the same, I know.

Similarly you could make a script that checks if the note is in inventory and destroy it (even in a burst of flames and with a message saying what happened) as soon ase the player walks out of the room with the note. If they had not read it, too bad