The bible is to history what Miami Vice is to police work. It covers very small, very selective parts of history and mixes them in with a lot of morality tales (Jonah, Job, etc.) that have nothing to do with the history of the human race. Notably, the bible omits the histories of most of the people on this planet, selecting only the history of the Jews and early Christians. The Phoneticians, Romans, Gauls, and Greeks are only footnotes. The Mongols, Celts, Native Americans, and Aztecs are entirely missing from this “history book”.
As for John being the oldest gospel, I believe that honor belongs to the Q Gospel, which is of course missing from the bible.
As for “planting seeds of doubt” I would say that those who espouse the bible as a testament of truth have a huge onus of proof to defend given the extreme claims that come with the book. As this is the basis for many legal and political decisions that Christian and heathen alike have to live by, I think skepticism and doubt need to be the cornerstone of any inquiry into the bible as authoritative text. Simply saying it’s authoritative does not make it so, any more than saying Dianetics or the Book of Mormon are authoritative because people believe their god has instructed them through it.