I like this idea actually. Never played a MUD but a fair way of implementing permadeath would work. If you are crazy enough to keep testing the limits of how low you can go then your character should die as you stopped using reason. People won't necessarily self regulate but the risk of major loss is always a game changer.
Dropping inventory could present some rather tricky problems where guildhouse keys are concerned. Inventory dropping would have to exclude some items, but weapons, tria, and trinkets should be fair game. In mabinogi you can drop things if you die and if you choose to respawn in a city, you can retrieve your items from lost and found at a price.
Maybe it would work if when you die and come back you can get your stuff from a lost and found in the nearest city for a price. Or maybe upon dying, the death guardian will take some of your stuff for his own purposes but will let you buy them back at a cost or do a favor (quest) for him.
Or maybe permanent stat loss would work (you would be able to build back up, but you would have to.
). Not major, but if you loose a level or three
in everything but intelligence every time you leave (and maybe start loosing in intelligence for yo-yoing) then maybe that would slow the amount of people dying. If nothing it might make people consider RPing recovering. And it might open up a new plot line for people as you could attempt assassinations and whatnot much more easily during these times.
Exceptions to this might be dakkru worshipers, possibly black flame worshipers, and those with a decent amount of dark way training.
Also, those with high factions with their god's might get a bit of "dying forgiveness" from their gods and would be one of the reasons for justifying worship. I believe it used to say in the atheist description that they weren't granted any succor from the gods when they died since they didn't worship. There would have to be consequence and partial exemption for that to be valid.