Joseph,
Regarding the “evidence” for a young universe, that position is not specified directly from the Torah but from Seder Olam Rabbah; there are other sources from our mesorah that would permit an ancient universe. Rambam, Ramban, and especially Rabbi Avraham ben HaRambam all agree that there is no chiyuv to believe the literal truth of any particular midrash/aggadata. Rabbi Avraham’s position is very clear that on that is not the purpose of midrash/aggadata and this position is accepted as seen by the fact that his essay forms the preface to the Ein Yaakov.