Perhaps it's just a classical case of two proponents arguing from opposing sides of the nature vs nurture debate.

Yes, I believe you are correct. That is exactly what we are discussing when we get down to the very core of the subject matter, and if thousands of years and millions of great minds could not have provided a clear answer, it's very doubtful that we shall here.

Nevertheless, there is a couple of things you mentioned that I would like to propose a dichotomous perspective towards, much like in the case of when you stated that natural means being true to what God has given you.

When a child hears the word "faggot" thrown around as a derogatory, dirty, word and then hears that word interchanged (as if synonymous) with the words "gay" and "homosexual", that builds a connotation that reflects negatively within the individual. It can, and often will, build up bigotry around the label(s) that's most associated with the words and create shame and disgust within the individuals that experience homosexual feelings, which is, IMO, one of the major causes of suppressing them.

While this may be true for some, my personal observation in life has shown me that it does not apply for everyone. The human mind is a very complex thing and each and every person has a different way of processing information, just as we all have a unique way in which we are affected by that information.

Where some would hear bigotry and then end up a bigot themselves, there are some who empathize with the victims of this bigotry more than with the bigot. If one has also suffered persecution or ridicule in their life, then that empathy can manifest itself in a strong connection to the victims (in this case homosexuals). Now for most, this would be nothing more than a shared understanding of the plight of life, yet for others, that shared persecution could create the illusion that one must also be gay and that's why they have suffered in the same way. What we consciously think about, is only 10% of what actually goes on in our mind. The unconscious mind makes more decisions for us than we are aware, and is for the most part, the true driving force behind our life choices and the path we take.

Neuro-plasticity has revealed to us the complexities of the brain, and how the more we see something the stronger the bonds in our minds associated with that particular thing becomes. So someone who was heterosexual and as such was not sexually aroused by the thought or sight of another of the same gender, after being subjected to same-sex couples showing signs of sexual arousal numerous times, will eventually develop a neuro-pathway in their mind that will tell them, on an unconscious level, that they should be aroused by the same sex.
Cognitive dissonance can prove to be a powerful defender of such shifts in perspective, but sooner or later, long term subjection to this sort of thing is always going to lead to that pathway being formed in the brain.

While there are powerful hereditary factors determined by genes relating to personality, I think a notable one would be temperament, these are determined by hormone regulation and even they can be ultimately overridden by nurture over extended periods of time, because human behaviour is mostly learned, not created.

People generally don't want to feel different, that's where the majority of the ostracization/ persecution comes from -

I think for every person trying to fit in, there is another fighting for uniqueness, especially in today's world were the public education system cripples our sense of individuality before we even get the chance to see it develop. I strongly hold the position that a number of homosexuals and transgenders are driven to their decision by a desire to stand out amongst the crowd after leading a life of essential invisibility.

My point is, there are a number of root psychological causes that could lead one to override their body chemistry on a subconscious level and become genuinely homosexual or transsexual. I am not asserting that there are 49/50 in this category who are pretending for the sake of it. No. Quite to the contrary, I believe that they believe they were born that way and it was inevitable to happen. I just think that 49/50 of them, having not been subjected to the perverted nature of the world we reside in, would not have been confused about their sexuality nor their gender.

I still think that we must all exercise tolerance in everything we do, but that doesn't mean we need to exercise ignorance. If you allocate even two hours to look into the pioneers of the LGBT community over the last few decades, where they received funding from etc, it becomes evident that there are forces out there who are intentionally exposing the masses to this on an unprecedented level. It's not about acceptance. It's not about unity and coming together. It's, I believe, something a lot more sinister. One thing is for certain though, we will never find out what the true agenda is as long as everyone wants to think that there is nothing going on, or are too afraid to express any concerns they may have for fears of being labelled closed minded(ironically).