Labyrinths discussion

This tale of a fictional theologian named Nils Runeberg is very intriguing. Does anyone know anything about this name and where did Borges come up with it? Are all the footnotes made up? I have always thought that the story of Judas is strange; his betrayal almost seems unnecessary. I mean why should the priests pay him 30 silver coins to show them where (or who) Jesus is? Why is that such a job worthy of 30 silver pieces? and what's with the kiss? In both Mathews and John it is mentioned that Judas kissed him [Jesus] tenderly...why? Strange fellow huh?