Hooberus,
The bible doesn't seem to be such an accurate source of chronology or history if you have such a large margin of error. How can you justify that? How can we trust the bible's history if it can't even give us a reliable date for one of the most significant eras of human history? Why should we trust bible believers who can torture any interpretation out of the scriptures they want? If the bible is so authoratative, there should be mass consensus.
Regarding your question about dendrochronology disproving the flood:
It might interest you to know that trees go back at least 8000 years without being disturbed by Noah's flood! Dr. Charles Ferguson of the University of Arizona has, by matching up overlapping tree rings of living and dead bristlecone pines, carefully built a tree ring sequence going back to 6273 BC (Popular Science, November 1979, p.76). It turns out that such things as rainfall, floods, glacial activity, atmospheric pressure, volcanic activity, and even variations in nearby stream flows show up in the rings. We could add disease and excessive activity by pests to that list.
http://www.infidels.org/library/modern/dave_matson/young-earth/specific_arguments/tree.html
You have argued that the flood may have happened between 4500 and 7500 years ago. Are you now going to argue that the flood may have happened over 8200 years ago? If so, then you must have some convincing justification for this.
rem