...if a JW felt in his heart that homosexuality was okay, but believed that his heart was wrong and the Bible was right, that would be a moral choice on his part.
Perhaps, but it would be a moral choice based on the manipulative teachings of others. It does not allow the individual to research the subject and determine if his current belief system is accurate.
I am a prime example of this. While I was a JW, I knew I was gay. I did everything I could to avoid contact with other homosexuals, because I believed that the Bible taught homosexuality to be a sin. I did "slip" once while I was a JW and had a brief encounter with another man (for which I was given private reproof).
After I left the JWs, I independently studied the scriptures in the original languages and discovered that the supposed condemnations against homosexuals were not valid translations of those passages, that they were actually condemnations of pagan fertility ritual, etc.
Moral choices do not necessarily mean informed choices.