"Then why did the animals need to be saved? Why spend 120 years building an ark for a local flood? Why build a boat THAT big? It had a capacity of 522 railroad cars. and was taller than a three story building. "
Exactly the points anyone with common sense would raise. There is no need to save the animals if the whole world would not need to be saved. There was no global flood. The geology shows it. It is an interesting story, but not one that makes much sense spiritually and none at all scientifically.
http://www.talkorigins.org/faqs/faq-noahs-ark.html
No, the geology shows there was a flood. The scientific community is finally acknowledging that catastrophism played a much larger roll in the fossil record, but they haven't yet come to the knowledge that Creationists have had all along, that most of the Catastrophism they are seeing, were not HUGE local events. They were one big HUGE GLOBAL event.
To me, the works of Moses get their authority from the miracles that God used in bringing Israel out of Egypt and to confirm Moses as His prophet. Future prophets get their authority from the tests that Moses laid down and the occasional miracles that God used to confirm them. And it's my understanding that's what the Jewish scholars used to determine the Old Testament canon.
You throw out Genesis, then you don't have a basis for keeping the other 4 books of Moses. You throw them all out and you know longer have a basis for choosing the Biblical books over any books.
The only basis you have would be the miracles that confirmed Jesus. But then Jesus quoted those books as authoritative, refering to Moses, Noah and to Creation.