A Supranatural Sexuality: Further Problems for Those Who Argue "from Nature"

In my recent comments on homosexuality, I attempted to demonstrate that arguments based upon the ‘naturalness’, or lack thereof, of homosexuality cannot be based upon Gen 1-2, when we take those texts at face value. Rather, those who read Gen 1-2 as a condemnation of gay unions, tend to filter the text at hand through the lens of a particular (and rather simplistic) reading of Ro 1. According to these exegetes, Ro 1 suggests that homosexuality is unnatural, and therefore immoral.
Now here is an interesting idea.
Paul’s comments about the ‘unnatural’ nature of homosexuality are based upon his experiences as an observant Jew, living within the diaspora, during the first century CE. From this perspective, I suspect that a case could be made that Paul’s comments about what is ‘natural’ or ‘unnatural’ are based upon his observations of nature. That homosexuality would be considered ‘unnatural’ is just as obvious as, oh, the fact the men should have short hair and women should have long hair (1 Cor 11.14-15: “Does not the very nature of things teach you that if a man has long hair, it is a disgrace to him, but that if a woman has long hair, it is her glory?”).
This leads to two further ideas.
(1) Those who wish to cling to the ‘natural’ argument in Ro 1, need to demonstrate how this ‘natural’ argument is more significant, long-lasting, useful, or whatever, than the ‘natural’ argument Paul makes in 1 Cor 11. (Good luck with that!)
(2) Those who wish to cling to the ‘natural’ argument in Ro 1, now do so against what we have observed in nature. Now this is interesting because, if I am correct that Paul believed that the unnaturalness of homosexuality was actually easily observable in nature, then this position risks contradicting itself. You see, it is now clear that (for many people) homosexuality is not a choice, and homosexuality has also been well documented within nature, and within the actions of other species. In response to these observations, those who wish to assert that homosexuality is ‘unnatural’ simply assert that these things are signs of the truly pervasive nature of the fall. But note what then occurs: (a) that which is ‘natural’ is increasingly defined by that which exists outside of the realm of nature — and so talk of the ‘natural’ is increasingly supranatural (i.e. there is essentially no proof from nature — say the discovery of a ‘gay gene’ or whatever — which would then be convincing to those who hold this position); and (b) Paul’s method of argumentation is reversed and, seemingly, discounted. Paul makes an argument based upon his observations of what appears to be obvious in nature, and now some Christians wish to affirm Paul’s argument while simultaneously arguing that we should not make arguments based upon our observations of what appears to be obvious in nature!