First of all, thank you for your thought-provoking questions. I believe it’s good for us to challenge ourselves with fresh study. Scripture indicates that Lucifer, in cryptic tandem with the king of Tyre, were “the seal of perfection, “full of wisdom and perfect in beauty” (see Ezekiel 27:3; 28:11-19). Then Isaiah affirms our understanding of Lucifer’s decision by speaking with authority that Lucifer’s goal was to replace God (see Isaiah 14:12-15). Further, Isaiah refers to Lucifer as the Morning Star (ibid), which translated to literal Hebrew is “brightness”. This imagery is further depicted in Revelation 12:4, 7 and 8, wherein the dragon (Satan) is rebelling against God and is followed by one third of the angels. From these passages we see that the bright morning star, who was created in perfection and beauty, chose to rebel against God thereby was cast from heaven to roam the earth as a lion, ultimately to be defeated and thrown into the eternal lake of fire. Even Jesus tells us that He saw Satan fall like lightning from heaven (Luke 10:16-18). Jack Cottrell underscores these truths in his book The Faith Once For All (170).
Now concerning the second question, I affirm that scripture teaches there is no redemption for Satan and his demons. The strongest evidence is found in the teaching of Jesus Christ. For example, in Mark 1:21-28, while Jesus was authoritatively teaching the truth of scripture a demon afflicted man cried out to Jesus affirming that Jesus was the son of the Most High God and Jesus told him to be quiet. Forgiveness was not an option for the demon, nor was the proclaiming of the gospel. Again, in Mark 5:6-13 the demon afflicted man ran and threw himself down at the feet of Jesus but salvation was only afforded to the man, not to the demons named Legion. While there are countless other passages, I will close with one final quote. While the gospel is God’s salvation for mankind, hell was “prepared for the devil and his angels” (Matthew 25:41). Only one conclusion can be drawn from this verse of scripture (indeed the entire word of God), there is no redemption for Satan and his demons.