I tend to take the position of my Church(Catholic) and much of what you infer is true in some regards e.g. some may be predisposed cause unknown with an attraction to the same sex. I would suggest that some may love deeply another as well without having to engage in sex with them e.g. a family member...
Anyway, being predisposed to an activity may lessen or remove culpability (guilt); however, does not lessen the negative aspects of the act itself.
I would suggest that if one is predisposed to an activity and if they begin actually engaging in the activity that this reinforces its 'hold'. The longer it is practiced the more habitual and entrenched the attraction becomes. As well, the more one is told (conditioned) to believe that what they do is okay -the more it is as well entrenched and the more it takes 'hold'...
From my perspective, opposing the homosexual agenda entails primarily opposing those who use government --to promote state that homosexual sex is neutral, equivalent or good, opposing those who wish to use government to indoctrinate children into accepting the activity as good, opposing those who seek government mandated rights and privilege premised in the activity, and opposing those who promote suggest government funded and sponsored propaganda regarding homosexual sex e.g. it is "okay" or "it will get better" as was recently seen in a public campaign to fight bullying.
Opposing the homosexual agenda is not and should not be about judging whether or not one is legitimately predisposed and suffering a heavy burden -one can not judge anothers heart.
As well, opposing the homosexual agenda is about His love which is rightly displayed not only in loving the person but as well in rejecting the activity. Just as when one loves their children -this love not only encompasses acceptance it as well encompasses guidance -acceptance and guidance involve both encouragement and discipline...