Well, I liked the Finale because it was more about the characters. Seeing the points where the various people made the decisions that ultimately brought them to being part of the RTF made the whole story just that much more complete to me. Also, BSG always had bits of ambiguity all through its mythology, leaving questions unanswered is just par for the course here. IMHO, Ron Moore was right, because the show was always centered on the characters, not the plot. Cavill kills himself because he knows that even if he could get off Galactica, his dream of one day becoming more than human (and, of course, gaining immortality) will never come true.
As for "finding a rock to live on", what has become clear during the run of the show, is that habitable planets are about as rare as they are in reality. They had to land on our Earth, because there were proto-humans already living here, which not only allows but ensures humanity's survival. As for laying the groundwork for our mythology....Didn't you hear Lee say "we'll give them everything that was good about us"? He believed that, on a philosophical level, humanity wasn't ready for the level of technology it attained on the twelve colonies, and that giving the people of Earth a headstart on philosophy, rather than technology, might be a good idea.