Reform Judaism has a long and proud history of working for the full inclusion of LGBTQ+ people in Jewish life and for their full civil rights.
Reform Judaism accepts in broad outlines the traditional definition of Jewish status: to be a "Jew" one must be a member of the Jewish people, a status obtained either through birth or conversion. Jewish identity is not determined purely by the individual.
Mazel tov on your upcoming wedding. Although different rabbis may respond differently, nearly all Reform clergy would be happy to work with you.
Being called to the Torah to chant the blessings before and after the Torah reading is a great honor.
Jewish law does, in fact, permit organ donation! Whatever you have heard, whatever you thought you learned, set that all aside. Jewish law permits us to sign our donor cards and, when someone we love dies, to use their body to save other lives
Rather than answering this question myself, I’m going to refer you to this great answer by Dr. William Berkson, director of the Jewish Institute for Youth and Family, which originally appeared in Reform Judaism magazine
In answer to your question, "Can a Reform Jew believe that God gave the Torah at Sinai?" I think that the most honest answer is, "Yes, but..." Let me start with that "but.
A sukkah is a temporary, hut-like dwelling built during the holiday of Sukkot. (In fact, the word sukkot is the plural of sukkah.)