I guess the 0 level idea comes from the PCs lack of understanding and context their sure to experience when first waking up. The idea has been that when they level, they will of learnt or 'remembered' enough to warrant the increase or 'rememberence' of power. The term 0 level is used loosly and stems from years of 2E abuse. Wether their actually 1st level or 0 level is a fairly mute point, as long as their less skilled than a standard 1st level character.
Zappo, I see your point about the PCs ability to speak and attend to basic needs. This comes back to my question about amnesia and its effects. I like the idea that certain primitive instincts work on a subconcious level and therefore, perhaps, are exempt from memory draining effects. In this case, they will soon remember or instinctually seek out food and water (hopefully not styx water...to many times), and grasp the ability to comunicate, which would of been learnt early in the PCs development or life.
But your right, inability to comunicate...whether by a show of force or plain lies or bluff will get you killed quick in Baator. I'd realised this very early in the piece.
Maldur, my players are fairly experienced so I'm confident they will take any possble spoilers from Torment with a pinch of salt. I certainly will. The basic premise behind Morte is fairly loose and open ended. I can see that some PCs may be bias because of the game and other spoilers about Mimirs...but the fact their PCs don't remember this, should add to the tension...
