I brought this up in another thread and think it should have it's own place.
If there is a very strict alignment system where killing good players is very difficult or impossible to redeem, evil players (or even other neutral/good players from other towns) will be able to use "good" or "neutral" spies or sabateurs with a significant amount of security.
There must be a way to kill neutral/good players without an irrevocable slide into being evil. If there is not a game mechanic to prevent this, then good and neutral towns will lose their players over time because the players were defending their town. Even craftfolk might find themselves in a bad situation. If your master blacksmith finds himself being attacked by Joe Noob evil alt, with no choice but to die and lose a great deal of valuable items, or kill a "good" player... Once might be not that big a deal, but what if it happens half a dozen times over a period of several weeks?
I promise you with 100% certainty that if there is no way to redeem/pardon your character or prevent an alignment hit in the first place, neutral and good towns will be crippled frequently by their inability to kill spies without taking alignment hits.