Whoooooooooshhhh. Such a long read. But fortunately it is worth it. Honest to say, i have held several of this misconceptions myself. Notably on the pregnancy length and salt intake.
Actaully, on the question of preganancy, the belive that it takes just about 9 months, is so popular, it is part of the educational curiculum in my country, and i bet in most other countries.
So basically, the misconception, if you are right, is an indoctrination some of us got/get from school.
You have here shade a good light to most of these misconceptions, and i have to say, several of them caught my interest. I should be able to check them out, and read some more. Much obliged.