Let me say first that I disagree entirely with your view of the Establishment Clause, and further state that you can't support it with discourse from the founders - "Establishment" does not mean "an organization" - it means "the establishment by the government of state-sponsored religion." The use of the word in the convention clearly referred to the establishment by government of religion - not a formal organization that Congress was prohibited from reaching with legislation. Your interpretation would be that Congress can not make a law about an organized Church, but can make one about a disorganized Church. Of course, the level of organization - what is an Establishment and what is not - was never discussed by anyone.
In addition, the free exercise clause refers to the free exercise "thereof" - what is "thereof"? It is whatever is protected in the Establishment Clause.
If something is not covered by the Establishment Clause, it is not covered by the rest of that same sentence, in the Free Exercise Clause. Any other construction is, to be kind, tortured. Moore states that these religions are not "religions" for purposes of the Establishment Clause. Therefore, they are not religions for the Free Exercise Clause. This is entirely consistent with his statements that non-Judeo-Christians can worship their God ONLY because our God lets them.
In order for it to be establishable, it needs to be organized enough to be an organ of the state - a la Church of England.