What is the Reform position on clergy officiating at the wedding of a Jew to a person brought up in a different faith? My fiancée is not Jewish, and doesn't want to convert at this time. We want a Jewish wedding, and plan to raise our children as Jews.
Historically, since the Rabbinic period (post 70 CE), Jewish status was passed down by the mother.
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.
Since the Rabbinic period, Shavuot has been tied to the story of receiving the Torah. Connected to this, Shavuot has come to be dedicated to the idea of Torah study and Jewish education.