Regarding co-existing, dinosaurs were prevalent in the dryer regions and were the dominant species, but mammals were among them. According to the bible lifespans were huge back then, Noah being the oldest person on earth only died 300 years after the flood. Thus there would only ever be a few humans dying concurrent with dinosaurs, but to find them together virtually impossible due to variation in habitat and human burial habits.
Even if this were so and the habitats were so separate and distinct, why do we not find human remains in rocks of equivalent or correlative age as the dinosaurs? Why do we find no trace of humans before the flood which predated the end of the dinosaurs? Any way you cut it, there should be evidence of coexistence.