To prevent an overly long response to your thoughtful questions, let me make a crass commercial plug --- please read my book "Alien Agenda" (New
York: HarperCollins, 1997). I assure you that most of your questions will be answered in the book.
But I will say, beyond any question of a doubt, that the UFO phenomenon began long before Roswell. In fact, it began long before the Bible was
written. Erich Von Daniken and Zecharia Sitchin are two authors with which to begin your study of ancient UFOs.