Should we changes the genes to ensure there are no gay children?

Should we change the genes to ensure that nobody has a different mind than the average?

Should we change the genes to ensure that everyone matches the fitness, height, and other standards that society typically encourages?

Absolutely not. It creates the same negative effect as eugenics. While genes that directly cause massively damaging things like blindness are acceptable to edit out, any further than that is unacceptable to me.

Imagine we took someone like Stephen Hawking, "fixed" his genes at birth, and he was now an average 40 year old working a desk job, with a good body, and a good brain.

And, yes, these people will live worse lives, be ridiculed, bullied, and disliked as all those weak, atypical, or different end up being. They will live worse lives as indaviduals thanks to our refusal to fix them. Perhaps Hawking is happier with a good body.

However, for the good of society, for the health of our nations, families, and so on, we can't all be average, typical, or normal.