Yeah just because there was a massive flood at some point in history doesn't mean it was actually Noah's ark. In fact, most historians believe that this event may have served as inspiration for the story, but not as the actual historical event. Say there is a huge disaster that affects a certain area and a few decades later you want to write a religious text that people would believe. You might use that event in your story, so your readers would say "oh yeah, i have vaguely heard about that, so it must be true." And while everyone has the right to believe what they want, that doesn't make them right or justified. I have the right not to believe in the law of gravity, but if I jump off the roof of a tall building, gravity is still going to be there.
As far as evolution goes, however, perhaps some misunderstood what I was saying when I said that it's just a theory. I think that if you look at the entire history of science, scientific discovery has basically meant doing away with old ideas and replacing them with new, better ideas. Take physics for example: Galileo was eventually proven wrong, Newton was eventually proven wrong, Einstein will eventually be proven wrong because his theory doesn't take into account quantum mechanics. I think that, with this pattern evident, it's not the best idea to accept evolution wholeheartedly. While I think that evolution does exist, it's only an important piece of a larger puzzle. It will have to stand up to many years of scientific process before it can be accepted as a law.