Your dates on Sargon are correct but the Bronze  Age Mesopotamian precultures (Ur and Uruk) from which Babylon grew and from which the people of the area drew there cultural experience go back much further. . 4th Millenia BC. Prior to that there were neolithic nomadic cultures in the area. The Babylonian account of the flood legend was the Gilgamish epic. Although the epic is attributed to the Babylonian period, the flood legend predated the period in which the poem was written

With respect to the Minoan civilization on Crete the prepalatial culture dates from 3,650-3,000 BC. Pre bronze age neolithic culture dates back to 7,000BC.

Your assessment of radio carbon dating is correct. However I believe I mentioned a number of dating methods employed to establish the fossil record. Radio carbon dating will be used where it can be employed. There is also a certain degree of statistical error to be expected., depending upon the sample used and whether it has become contaminated. Geologists can also date the fossil record by the date of the rock strata in which the fossil is found. With respect to the die off of the dinosaurs 65, 000,000 years ago the most widely accepted theory at this time is that an asteroid struct in the area of the Yucatan Peninsula. It threw dust into the atmosphere which was the equivalent of nuclear winter. The plant life was the first to die. The herbivours were next. The carnivours were next. It took a number of years for the dust to settle, but when it did it created a layer of sediment (strata) and became part of the fossil record, which was discovered in recent years and dated at the 65,000,000 year mark by geologists.