1. The Gospel of Judas tells us nothing about the historical Judas, if indeed he even existed. This issue seems to be very confused in the public mind. These ancient gospels were fictions in terms of what we today call "historical facts". This text wasn't written to tell us what Jesus really said to Judas. It is a theological text. In this case, we have a Sethian Gnostic writer who is using stories about Judas the demon to make a new point. He is criticizing mainstream Christianity - its doctrines (Christ's death functioned as a sin atonement) and its practices (the eucharist which reenacts Christ's sacrifice and atonement).
2. When we translate words like daimon, we should be doing so by comparing our text to texts closest to the traditions and age of the text in question. Why? Because the thought-world assumed by the text determines how words are being used. In this case we need to be looking at Gnostic texts in the second and third centuries. I have found so far about 50 instances of the word daimon in Gnostic literature. It means "demon," beings in opposition to the supreme God, and creating an imperfect world out of their rebellion and ignorance.
(1) Trimorphic Protennoia (Sethian, early 2nd c.): mentions Archons, Angels, and Demons (35.17); calls Ialdabaoth the demiurge "the great Demon" who produces the cosmic realms (40.5); mentions the "chains of the Demons of the underworld" which the redeemer broke (41.6).Gnostic texts use this word to mean nasty Powers, Archons, entities within the cosmic sphere, with creative and tempting powers. The Christian literature in this period, as well as the NT, uses daimon to mean demon too.
(2) Apocalypse of Adam (Sethian, mid 2nd c.): refers to the Archons Solomon, Phersalo and Sauel who sent out an "army of demons" to seek out Mary the virgin to try to kill Jesus when he incarnated (79.5).
(3) Gospel of the Egyptians (Sethian, late 2nd c.): Nebruel is called the "great Demon" twice (=one of three terrifying demiurge Archons in 13th realm) (57.10-20); the demiurge Archon is said to create "defiled (seed) of the demon-begetting god which will be destroyed" (57.25).
(4) Zostrianos (Sethian, early 3rd c.): fragmentary reference to demons (43.12).
(5) Testimony of Truth (Gnostic, late 2nd c.): interprets the leaven parable to refer to the "errant desire of the angels and the demons and the stars". These figures are associated with the Pharisees and the scribes of the law who belong to the Archons who have authority over them (29.17); speaks about fighting against the Archons and the Powers and the Demons (42.25).
(6) Apocalypse of Paul (Gnostic ?, 2nd c.): speaks of principalities, authorities, archangels, Powers, and the whole race of demons.
(7) Apocalypse of Peter (Gnostic, 3rd c.): in context of discussion of Archons, talk about dreams comes from a demon worthy of the person's error (75.5); the physical body is called an "abode of demons, the stone vessel in which they live" (82.53-54). The Testament of Solomon says that Solomon confined demons to these sorts of vessels.
(8) Authoritative Teaching (Gnostic ?, beginning of 3rd c.): speaks of the "force of ignorance and the Demon of Error" (34.28).
(9) Concept of Our Great Power (Gnostic, early 4th c.): refers to the dissolution of the Archons following Jesus' crucifixion. The are referred to as evil demons who will be destroyed (42.17).
(10) Paraphrase of Shem (Gnostic, 3rd c.): a series of 35 passages which speak of demons who are part of the darkness which work to create this world. For all the references, see The Thirteenth Apostle, p. 186 n. 20.
But can't daimon mean "divinity" whether for good or evil. Yes, as I write in my book The Thirteenth Apostle, in Greek philosophical literature where the cosmos is not envisioned as mostly or entirely under the rule of evil beings. If the Gospel of Judas were a Greek philosophical text, we could argue for a more generic translation. But it is not. It is a text of the Sethian Gnostic variety where the heavens surrounding this earth are populated by Archons and their nasty assistants, evil powers and demons. Here Judas is the 13th Demon, a designation for Ialdabaoth.