Obdurate, i love ya already. Great to have a debater here. Okay, as a religious follower, i will defend thy bible!
The bible has changed over time, no doubt about it, as it was translated. The OT, Old testament, is REAL Jewish history. But, anything before the writing of Abraham may not have happened, and I will explain that in answering to your 2nd question.
The NT was written by the followers of Christ, and take into account that they were written 40+ years later, and each around different times. Mark wrote his 10 years before Matthew, Luke 15 years after Matthew, and John around 90 AD, or 5-10 years after Luke. Each Gospel increased in detail. Now, since we have multiple accounts, I say it's safe to assume that this was not fabricated. Also, the Bible is not biased, wanna know why? Each Gospel [writer] had a different audience, the Jews, gentiles, and Romans. Now, since Christianity extends to all different kinds of religions, it wouldnt have grown as big as it is if it were biased. The gentiles, Jews, and Romans wouldnt have converted if it were biased. Yes, i have read historical accounts, take the crusades, where Christianity was corrupted IMO, where you would have the Muslim POV and a Crusader POV. When comparing my historical documents with the Bible, I cannot pull out any bias in the writing of the Bible.
Logic is Science, what we learned through trial and failure. What's learned becomes logic. We learned that it's "impossible" to part water like that, but with "divine" wind, it could be possible. This is a stuck point, because we has humans can only "Believe" and "have faith." At this time, my mind is blank on the subject... I may come to argue about this at another time

.
To answer your second question...
Again, the concept of changing languages and times it were written must be taken into account. If we think about, how likely is it that we spawned from 2 people, Adam and Eve? I personally believe in the theory of evolution. I believed God created space, or the Universe, and it has evolved into what we have today. The reason why? Take into account of the educational capabilities of the people in the past. As a child, the best way to learn was from pictures, songs, and the general word, imagination. The intellect of this time was lower than ours, so to explain things they don't understand, they used stories. As for Revelation, the last book of the Bible and the New Testament, it is highly symbolic because it was written by the Gospel John. John's personal gospel is the most symbolic, it's excluded from the other 3 (I believe they are called Evangelists, or synoptic gospels, or another term I can't remember right now.) John was the only apostle present at the time of Jesus's crucifixion, and since he was the last of the gospels, he wrote it in the most symbolic way. Revelation is the reflection of Judgment Day, a Day we [humans] will never know for certain. Through the use of Science, we may be able to try and predict, but you can't predict divine intervention. So, I say we must take into account of the time it was written, who wrote it, and why it was written. Glad to debate on this further, when the time comes...