Does Christianity allow allegorical readings of creation and the deluge? Please forgive me, I'm not Christian but I have wondered: Why do Christians seem to try to prove Noah's flood or a young earth? Considering the overwhelming evidence for human and geologic history that there was no global flood that wiped out life on earth or civilizations and that modern humans have been around for hundreds of thousands of years, can an allegorical reading of the beginning of Genesis be allowed?
Seeing as it is almost impossible for bias to not slip into our research, we will always see what we want to see or at least try to. Scientists will find reasons that such things aren't true while we believers will believe because we want to. Until 100% undeniable proof is found we will always debate this question. 

As for my opinion on the matter, no we should not try to find a deeper meaning of the scriptures. We should read in the lines of the scriptures and not necessarily between them. There are a few exceptions to this such as the book of Revelation which uses heavy symbolism, but most of it is explained so again I think we should let the bible translate itself. Here is some research into the wording of the days and so on.

In Genesis the day's may or may not have been 24 hours. That doesn't matter because there could have been any length of time after the earth was finished that god made man. If you look at Genesis 2:4-7 we see that there was no time span given between the finishing of earth and the creation of man. Man may have lived for only the past 6000 years, but because of the lack of details the earth may be much older. 

My answer then is no, the bible should be read as it was intended and thus as it is written.