I would love to see a good source on the "circulating around the time of Jesus" claim. I've never been able to track down anything credible on that front.
http://www.gnosis.org/naghamm/Pagels-Gnostic-Gospels.html notes the existing manuscripts date to 350-400, that "some" must date to somewhat prior to 180 AD because Irenaeus speaks of "other gospels", and cites a Harvard professor who speculates that the Gospel of Thomas "may include some traditions even older" than the official gospels. Those are fairly weak claims; do you have support for your stronger claim?
Is there any tl;dr versions of the above? I have curiousity about noncanonical writings, but don't have the time or inclination to go out and become a scholar of such things in order to sift wheat from chaff.
Me too. The earliest writings I know of are Paul's letters and possibly the Didache, and neither of them were written until a couple of decades after Jesus' ministry.
http://en.wikipedia.org/wiki/New_Testament#Dates_of_composit...
This view is not scientifically supported though.