So I went and made pixies OUTSIDER_CONTROLLABLE.
Ahaha.
I thought I could at least be successful as a socializing adventurer. But lack of CANOPENDOORS put a dent into my plans. Oh well.
A thing I noticed was "Stealth without skill: Best possible" and "Vanishing profile", so I decided to try and see how good I can be at avoiding hostile eyes. I went into the night until I was ambushed by bogeymen.
Well, apparently being in the "red" sector you will always be noticed. Or maybe it was that they were already looking at me. I should've tried entering stealth mode before I heard the cackling.
Anyway, what happened next is most interesting. Attacks passed right though, and although the bogeymen were able to grapple me, none of their joint locks did any damage or caused any pain. It did still cause some tiredness, since that's what my adventurer eventually passed out from, and then the game went into "auto-mode" while I was unconscious and they were still trying to break my limbs. Until the sun rose and they disappeared.
Unfortunately, exhaustion was apparently so down the negatives that my adventurer wasn't going to wake up (the moment he regained consciousness he would immediately pass out from exhaustion again).
My best explanation for this phenomenon is as follows:
The game likely tracks blood volume and tissue damage by cubic centimeters. Since a pixie's body size is exactly one cubic centimeter, none of his body parts will have a calculated volume above zero. Therefore, there is effectively no tissue to be damaged, hence attacks passing right through, and none of the locks caused any damage, pain or blood loss either.
Discuss.