1.
The Cainite "Gospel of Judas" isn't really confirmed yet as authentic, to the best of my knowledge.
It would have been, and likely is, the product of a group of 2nd c. Christians who were never considered mainstream. Apparently, they did lots of this type of work (writing great evil-doers into "Part of God's Plan") probably as an exercise in theodactic yoga.
2.
A very large collection of Gnostic Gospels, the entire Nag Hammadi library, is available here:
http://www.gnosis.org/naghamm/nhl.html
I don't see how anyone would either a) find structure amongst them, or b) find a conspiracy theory.
Standard dating for the authorship of even the synoptic gospels is problematic, with John ranging (last I heard) from 90-110 CE, so it isn't _that_ big a deal to describe any Gnostic Gospel as being from 100-200 CE.
Three, Truth, Philip and Thomas, seem right at home with Mark, Matthew and Luke. Some are perfectly consistent with Hellenic philosophical thought of that era. Some seem perfectly at home in the religion of the banks of the Nile.
If you are interested in this material, spend a couple hours or more reading the Gnostic Gospels. But I wouldn't waste more than a few moments reading anything _about_ them.
There seem to be two camps, those that want to make it all go away (and they are useless) and those that want to make it seem like the Real Secret comes from these works. I haven't found anything resembling a middle ground.
Dan Brown should get some (quanta) of credit for popularizing the existence of the Gnostic Gospels, but his theories (stolen, as they were, from decades old discredited pseudo-academia) are bunk.
Luke 19:27 (Kill all who would not make Jesus King!) Exodus 21:15-17 (Kill children who curse or hit their parents!) Matthew 5:17-18 (Nothing in the Old Testament changes until all is fulfilled!)