Decisions on bans should not have to depend on one moderator, I think.
1. I've seen people get banned for wishing death when it was obvious to me, within a chat context, that it was a joke, esp. given the fact that it was said between two friends. The rule was simply used by a third poster who saw an opportunity to get another poster banned.
The ban for wishing death was upheld right away.
2. I've also seen somebody in GM writing away his/her bitterness about a player by wishing that the player would fall and crash his head so hard on the court that the skull breaks open and the contents would spill out on the surface.
--> this person only got a "wishing injury" ban which is less lengthy than a "wishing death" ban (this to me is ludicrious: I'd like to find out how this can be categorised as "injury" when death seems a sure end of this scenario)
It's inconsistencies like that that will get people upset more than the rule itself, I feel.
So, perhaps things like that need to be a group decision or a majority decision rather than the action of one individual mod. This will often mean that the decision will be delayed until enough moderators had the time to vote on a decision but it'll cut down subjectivity even though you can not erase it entirely.
The task of a moderator is not easy and indeed, a lot of it will be open to interpretation.
Maybe - just a suggestion - we need some sort of poster's council: a fair selection of posters to assure a fair representation, posters who are not seen as impulsive, easy to bait hotheads. Posters who don't have a black-and-white view on the players. (good luck in finding enough of them) and you would need to be careful that the council is selected well enough so that popularity on MTF won't affect the way rules are upheld.
So, if there's an argument about a decision made by moderators, you can explain the case (with links to posts and such, to view the matter in its proper context) to the council and they'll get to vote on it.
This could give a decision a broader foundation if a decision by the mods is questioned.
(perhaps too complicated, though)
Personally, I think that the rule is very simple. Do not wish death, even as a joke.
Don't hide behind others if you are stupid enough to break it.