trans | (no subject)

Hello, my name is Faith, and I am a 17-year-old student looking for information. I am not transgender myself (though I am a lesbian and very recently in a polyamorous relationship), but I do have a transgender friend and I'm very interested in transgender rights. I've noticed that many people in my school and the area in which I live tend to be very transphobic, and in hopes of changing some opinions, I've decided to do my final project for my Ethics class on self-determined gender identity rights. Among other things, the project requires me to state one to three major arguments in favor of and against my chosen topic. I already have one point in favor (that being a statistic I've found: 50% of trans people commit suicide before the age of 30 if not allowed to transition in some way (socially, physically, or otherwise)), but I haven't been able to turn up much good, solid information beyond that. Specifically, on the opposing side of the argument, the most coherent argument that wasn't essentially pointless whining was "Because God says it's wrong." I can't exactly use that for my project.

In short, I was wondering if anyone in this fine community would be willing to provide me with some usable information. I need to have at least one argument opposed to self-determined gender identity rights (more feasible than "God doesn't like it") and hopefully one or two more in favor. Any personal experience or links to outside websites would be greatly appreciated. Thank you!