i think the currently solution is nice. but not great.
i think the amount of criminal acts should/could be added to the whole calculation of the strength of the ghost.
say 10 thefts is 1 vandalism.
10 vandalisms is 1 murder.
or sumesuch.
as long as noone is murdered (or enough damage done equal to a murder) the ghost shouldnt be able to perma kill.
just let every hit be a wound, no shp, just wound upon wound upon wound.
the stronger the crime(s) the stronger the wounds.
not killing the ghost in time could off course result in death if your wounds stack beyond your HHP.
this would add a significant penance, without being certain kill by 20 ghosts that are each 0.3 your power.
this would also still allow for smaller crimes to be commited without too much of a burden.
stealing 5 bars of steel would be the same as stealing 5 hay in this case, but meh.
the point is, more crimes stack to 1 bigger punishment, instead of multiple small ones.
permakill should also just be for when you do enough damage to other players to actually warrant(heh) it.