I do understand you thought process on this, but you are missing on very important point. God deals with the heart. You are proposing that as long as a person keeps his or her thoughts and actons in check, he or she will be all right. God does not work that way. The Bible teaches us that even when we give to others or the church, we are to do it cheerfully. God does not want us to have malice in our hearts about giving (I'll have to find this Scripture later). God can have absolutely nothing to do with sin. He even had to turn away from His only Son when Christ became sin for us. And about the ninth hour Jesus cried with a loud voice, saying, Eli, Eli, lama sabachthani? that is to say, My God, my God, why hast thou forsaken me?
(Matthew 27:46)
Please correct me if I'm wrong!
You believe that if heterosexual people keep their thoughts and actions in check toward the opposite sex, they are not committing sexual immorality, even though they are naturally attracted to the opposite sex.
You also believe that even if people who are attracted to the same gender keep their thoughts and actions in check toward the same sex, they still commit the sin of homosexuality only because they are attracted to the same gender.
I can see why you believe this! To you and to many Christians I'm sure, that is what Romans 1:24-27 says.
However, to me Romans 1:24-27 does not say that, though I could be wrong. I'm just being honest, and I am not in any way shape or form trying to justify homosexuality from a Biblical point of view. To me, Romans 1:24-27 is talking about lusting after or having sex with a person of the same gender.