Okay long thread. Just as a note, please keep on topic, issues about the validity or Christianity or religion, or even on the other end Scientific fundamentalists and atheists in general can go on other threads.
I'm not Christian myself, but I think I may have some advice. I was involved in the religious community, went to Christian school and whatnot, and have friends of a variety of religious backgrounds of the LGBTQA spectrum,, and a lot of this comes from being in such a background.
Yes, fighting scripture with scripture is hard, but often that's your only option, even if the other party plays the "I'm right, you're not" card over and over.
Yes, the Bible doesn't state anything about a "sex-change" being wrong, but those who believe it do be a sin will be quick to state the following: there was no "sex-change" when all this was written, it "kills your unborn children," "homosexuality is wrong" (often people will drag that in whether is fits or not). So this is not the best "come-back" for the super up-tight religious folks.
As for Leviticus and Deuteronomy, (hey that last one gets spell checked, awesome for me!~ I would have had to look it up), there are several interpretations, but here are two of the most interesting I've found. Many Christian scholars say these passages were mostly written for hygiene purposes like listing what not to eat because at the time it could easily kill you, or many people have a severe allergic reaction to it. Or, things we take for granted like ready access to baths and condoms, were not developed at the time. Another interpretation from reformed Judaic scholars is, and lets remember these passages were written by the Semites, is that the list of sins are all things that fall under acts that were used in the worship of other gods. Meaning, in a convoluted way, men can totally have sex with each other while eating a bacon cheeseburger, just make sure it's not while worshiping anyone outside of the ones approved by monotheistic bearded dudes. *yeah, don't tell your parents that last part*
As for God's plan, that you're "spitting in the eye of" and going to Hell. This site is not about being transsexual, but sometimes we need to open up with something more on "familiar ground." It is the path a very interesting man, a pastor, took when he realized homosexuality and what the scripture said were not what they thought they were and how he can to believe in the a "biblical affirmation of homosexuality." Like I said, not the same thing, but it touches many of the scriptures that get harped on by the religiously intolerant, and gives some great points about what many people believe is hard evidence of what God means, from a man who is still very religious. The site is:
http://godmademegay.com/