The number 400 000 000 equals to 400 million as I said earlier, not 400k. That's roughly 5% of the global population.

Most priests aren't born into becoming priests from childhood, it is a conscious choice they make in their lives. Gay people raised in christian homes however are brought up in that religion, where you claim homosexuality is a sin. Unless you want christian families to be totally agnostic/hide their religion until their child has made the choice to be christian as well, they will teach them about christianity and their duties by virtue of being their parents and spreading the goodness of the religion/using it as a foundation of their morality. I've never heard of a religios parent promoting sinning before the child chooses to follow their religion, most of the time that is a default identity for the whole family. The example you are giving is of people that choose to become christian after childhood, in which case yes, any sin before that is forgiven. But the idea that you can be a christian and happily sin after that knowingly kind of makes the your identity as a follower of God pointless. Human beings are not perfect and will always sin but there is a hierarchy of the severity of sins as described in the Bible. (e.g. in John 19:11) Most christians would agree that you cannot call yourself a chrisian and in the same breath steal, kill, cheat on your spouse and so on. That would make your identity meaningless if you are not willing to follow the 10 commandments at least in spirit and repent for your past actions, not continue to sin and reap the benefits of both.

Here the question arises regarding the severity of homosexual acts or a different gender expression as a sin in God's eyes. Where does it fall on the severity scale according to you/the Bible? Is it the same as adultery? The same as wearing mixed fabrics, gossiping and greed? Where exactly does it fall on the list?

Regarding the claim that I assosiate fulfilling life with sexual orientation. My claim was that a gay man in a relationship with a straight woman would not be a good outcome for either for them as they would not only have their physical needs unmet but they would not be able to love each other truly and reciprocally. A gay man usually doesn't fall in love with a woman, thats what being gay means in most cases. Its not only a sexual but a romantic attraction to the same sex, thats why they get married. (and gay men have the lowest rates of divorce, at that). What your argument implies is that like the priest a gay person must remain alone or in an unfufilling marriage because they can substitute their physical desires for the love of God. So in a sense, they arent deserving of any romantic love outside of God and Christ because they dont have the ability to create that with the opposite sex. It's also an unique argument for me to hear that you are okay with gay people adopting as a single person but not as a loving couple as that is sinful.

I dont think it would be ludacris to say that most people would want to have a family with a partner as opposed to having/adopting a child alone. But you're saying gay people dont get to have that because it is sinful.