I agree with you on needing evidence, and as I said before, he references every claim in his books, in his newsletters, and even on his blog. As to whether they are solid references, I don't know. Most of them are from medical journals and studies I don't have access to.
But either way, who benefits? His entire plain consists of cutting out things like salt, sugar and added fats, and only eating vegetables, fruits, nuts, beans and seeds in some order (as a very basic summary). What does he have to gain aside from maybe selling a book? Once you know the plan most people need nothing else from him.
As to your lone voice claim, I haven't seen that. He works with several doctors, nutritionists, and researchers (NOT just Oz) and seems to have a thriving medical practice that has helped thousands of people.
As to the rest of your concerns:
1. What courses? I've never seen him sell any courses, unless you mean site membership, which is optional and for support only if you need it. Unless he has stock in all the major produce growers of the world, I'm not sure what he truly has to sell once a person buys the book and follows his plan. Everything else (like supplements) is optional and for support only if you need it.
2. $7 one time, not monthly. I'm puzzled why why these aren't free too. Like I said, he references every one of his claims, if you're into that. There are hundreds of references to various medical journals, papers, studies, etc. in his book Eat To Live, for example.
3. I think he uses H = N/C not as a true math equation, but as more of a shortcut to help people remember to get as many nutrients per calorie as they can (which is fundamental to his plan). I'm surprised you and others are getting hung up on this (and with such ridicule) without even bothering to understand it in context.
4. True, but what's his incentive? To sell more produce? He doesn't sell a miracle cure, and I can tell you right now that eating the way he wants you to eat is certainly not simple for me and many others. One thing I've noticed is that the bulk of people coming to him seem to be those (like me) who have spent years in pain due to "incurable" diseases, or people who have already had multiple bypass surgeries and everything else, and are sent home to prepare for death. It seems suffering provides extreme motivation.
5. I can't disagree with you on this one.
I can understand your skepticism a little, but it's not as if his website is a long form sales letter with javascript BUT WAIT popups when you try to exit it. Isn't one function of a website, I would say the primary function even, to market something? He markets his ideas and sells optional products for the benefit of his patients. What's shady about that? No miracle cure diets, pills, "free reports", etc. No long form sales letters.
I'd just hate for people to live a life of pain and suffering believing "inflammation in the colon has nothing to do with what is eaten" when it probably does, and when something can be done about it that doesn't necessarily involve their colon being removed and/or an early death.