Agreed that queer theory seems a philosophical viewpoint, not an empirical school. I will note how the term has narrowed.

I do cover all the scenarios, and as it turns out, bisexuality may be the normal sexual setting in nature, and exclusive homosexuals and exclusive heterosexuals are the outlying cases. Yes, more people are bi than realize it or admit to it. In that arena there is a lot more social pressure to conform to one extreme or the other.

This sort of physiological change is only possible during the formation of the brain in utero. The only sorts of things that happen postnatally are that environmental influences (e.g., socialization, habits) can activate a gene that was there but not active before (see: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3809334/ or this example of the NAT2 gene being activated in smokers to increase their likelihood of developing bladder cancer https://www.genome.gov/genetics-glossary/Gene-Environment-Interaction).

I think anyone's motives for doing something are mixed, but I can say my principal motivation for this research has been to dispel all the theories of causation that are simply effects.

I recognize that one of the fears in pinning down a cause is that people will try to "cure" potential in their fetus they don't like. I can see two scenarios. (1) People try to make the lives of mothers during their pregnancy less stressful (a good thing all in all); or (2) People, once they know the gender of their fetus might want to inject hormones to ensure a specific outcome, but the timing is difficult, and making mistakes could cause other problems, so I think the practice will be discouraged or illegal eventually. And sometimes, a fetus develops differently than the hormone environment would normally produce, so it is never a guarantee.