I can see how some of this would be true. That whole part about human beings starting as female and then becoming male once testosterone is introduced is true. Therefore getting additional estrogen levels that are not normal for a man could certainly lead to a bit of effeminism, I suppose. Will it make you gay? I really don't know, but I imagine that you can't blame it entirely on soy products.
I don't know in great detail the inner workings of the female reproductive system, but I did take an anatomy class in high school and from what I know about the birds and the bees (I don't understand what either of those creatures have to do with the human reproductive process.) it makes sense to me that an enlarged uterus could be cause for infertility.
As for the other scientific studies, he doesn't cite any sources, he doesn't give specific years on some of the studies ("in the latest year we have data for, studies say..." (paraphrased)). The only year I remember him giving was 2000, and we all (hopefully) know that science can be wrong or skewed and more modern discoveries can prove the facts we knew a decade ago to be false. Just like Galileo's time when everybody thought the Earth was the center of the universe and everything revolved around it. I'm not saying what he said is not true. I just can't find out for myself that it is
true because no information is given to back up his claims.
When it comes to overpopulation; I honestly don't know any statistics about China or any other place people are living, but I seriously doubt China is overpopulated. I think if anything, it's probably Chinese propaganda and a method of controlling the people. Just because a lot of people live in a relatively close proximity it doesn't mean it's overpopulated. But that's another topic entirely.
While we're (back) on the topic of tofu making you gay, I say that being gay makes you gay!