To your first point the only doctor that found the microscopic parasites is a doctor that does the parasite testing himself with parasite specialty testing. Second of all if a parasite is not in the gi tract it is very possible it wont come up on stool tests even with a good technician.
The other questions you are repeating the same ideas over again. Let's see how many on the parasite forum have benefited from your ideas. It sounds like you can't accept that people on curezone have parasites and that's your right but that doesn't make you right. It's possible it can help some people with diet issues but for many with parasites it is a completely different issue.
If someone doesn't have parasites then lucky them but there are people that do and it can be tricky to diagnose and treat.