Rhesus,
I wonder if you perhaps misunderstand the purpose and assumptions of the challenge. I say that because you refer to things like Randi is "denying an academic forum".
The challenge has nothing to do with scientific research, or academic exploration. It is, instead, a challenge. There are two aspects to this, as I see it.
First, the challenge is not about science, but about the paranormal. If the claim to live on water & air alone is based on hithero unknown science, then the challenge does not apply and Randi would not test the claim. So I got a little lost when you talk about, for example whether we really know if vitamins are useful. I'll argue we do below, but, and this is important, if we really don't know that, then the claim is a scientific one, and not relevant to JREF.
Second, the challenge is based on the assumption that science can explain what happens in this world. The important term is "can" - this is not a claim that scientific knowledge is perfect, just that if you explore an issue deeply enough you can gain enough information to make true statements about how the world works.
This, of course, is not proven, and as far as anyone can tell, not provable. However, we feel that there is such strong evidence that this is in fact how the world works that we are willing to say it is true (not TRUE, in some absolute sense). Furthermore, Randi is willing to put up $1M dollars to back up the statement. This is _not_ based on "open mindedness" on this issue. A line in the sand has been drawn, that this is a reasonable assumption, so reasonable that claims to the contrary can be dismissed out of hand. It's a "put up or shut up" challenge, and of course there is some chutpah and showmanship in that.
You obviously agree with me that we can decide that things are true or false, otherwise the challenge would be meaningless. Furthermore, I believe that you agree that there is no point in testing claims, for example, that the Earth is flat. I think you would not agree that your conclusion that the Earth is round is you being "absolute" or close minded, but the result of an informed decision. If pressed, you'd agree that there's some possibility of being wrong, yet it's not enough of a possibility to seriously entertain the alternatives. The Earth is round. Period. It's a reasonable conclusion, not based on zealousness. (I'm not trying to put words in your mouth, just explain what I _think_ you would agree with). If someone said the Earth was flat , I assume you'd try to educate them, not seriously reconsider whether the Earth is round or flat. Randi doesn't seriously think the paranormal is possible. That's why he's bet $1M. He could be wrong, but he (and I) feel confident enough to assign truth values to statements about these things.
So, finally, about the challenge under discussion. Quite simply, the Breatharian claims are paranormal. They claim that they draw energy from their "chakra". So that makes the challenge applicable to JREF (unlike questions about whether vitamins are necessary, which is scientific in nature).
Randi has drawn a distinction between things he will test and will not test. Naturally people will dispute those distinctions, as you are. He won't test a claim that I can turn a person into a monkey just by thinking about it. He will test a claim that I can find water with a dowsing stick. I don't speak for Randi, but it appears to me that the distinction here is it's easy to confuse yourself and think you really are dowsing. You can't confuse yourself that you are turning a person into a monkey except through mental illness. So making the claim of person->monkey is either a product of mental illness or a lie. Sorry, no challenge for you!

It's how Randi chooses to spend his time, and I find it reasonable, though I do understand why others would draw the lines differently.
You point out that some believe the Breatharian claims, and a few do. They claim 5000 members worldwide, but many feel those numbers are inflated. In any case, only a handful of those claim not to eat at all. So it's not widespread by any means. Of course I'll consider other data if you have it
So, I don't believe for a second that people live only on water, no more or less than I believe the Earth is flat. Heck, on the Breatharian website the owner admits to eating a McD hamburger two hours ago - for "love", and to counteract negative vibrations, not nutrition. Right.... And they claim not to age. The guy is white haired. Sorry, I feel the statement "I prefer to keep an open mind, but not so open it falls out" applies here. If that makes me "zealous" and "absolute", I can live with that
