You correctly recognized that the passage in Isaiah 14, referring to Lucifer is problematic, though I am somewhat confused by your connections and conclusions. The plain simple fact is ‘Lucifer’ is not synonymous with Satan as 99% of Christians believe. In fact, the passage has NOTHING whatsoever to do directly with Satan, other than the King of Babylon was a bad guy, typical of Satanically influenced characters. The whole passage is a mocking of the Babylonian King by the prophet Isaiah.
Satan can’t be eaten by maggots
If the passage were in reference to a spiritual being like Satan then the verse before it could not say this:
Isa 14:11 KJV -  Thy pomp is brought down to the grave, [and] the noise of thy viols: the worm is spread under thee, and the worms cover thee.
Worms and maggots cannot consume the flesh of Satan in the grave because he is a spiritual being, whereas the King of Babylon would succumb to death like every other mortal. The character can ONLY be human.
While the Vulgate’s translation stuck, and even in the KJV, the word ‘Lucifer’ does little justice to the actual meaning the prophet was trying to convey.
Lucifer is the son of who?
While Jesus IS the New Testament bright and morning star, day star, etc. as represented by the most brilliant morning star Venus, the ‘Lucifer’ reference in Isaiah 14 is to someone else, Heylel the son of Shachar, although it is the same object. That isn’t uncommon in the Bible. The ‘Lion of Judah’ and the lion who walks about ‘seeking whom he may devour’ are both deadly predators. However, one represents the kingship of Christ while the other is referencing Satan. Jesus is neither literally a lion nor is he the planet Venus. Same goes for Satan.
The Hebrew transliteration of ‘Heylel, son of Shachar’ would be better understood if it had been left transliterated instead of using the Roman (Latin) name for Venus. Here is why.
The Canaanite Connection
In the ancient Canaanite religion they had many gods. The gods were considered the offspring of El (God) and Ashtoreth (Queen of Heaven). Ashtoreth was also known to the Babylonians as Ishtar, a very important deity to them and their king. El and Ashtoreth had, according to their lore, about 70 children including the Baal of the Bible. Two of Baal’s brothers were Shahar and Shalim, the gods of dawn and dusk. Shahar ALSO had a son which was HELEL. Whenever the Canaanites observed the planet Venus in the morning sky, they literally thought it was Helel, son of Shahar.
So then the passage comes into the context of a tyrannical Babylonian ruler who boasted of a heavenly lineage like Helel, the son of Shahar, grandson of El. In reality, the pompous king of Babylon was a mere mortal brought down to the grave, an object of Isaiah’s ridicule in a tradition the Babylonian reader would understand. A reading of the KJV passage with the Hebrew transliteration of the Canaanite names causes the intended meaning to become clear.
Isaiah 14:12 How art thou fallen from heaven, O Heylel, son of Shachar wailing! [ How] art though cut down to the ground, which did weaken nations!
The king who thought himself as high and mighty as the heavens was brought low, wailing (crying like a baby) and defiled as a maggot eaten corpse in hell. Incidentally, the KJV left out of the passage H3213 (yalal), which means howling or wailing. I’m not sure why they omitted its interpretation.
Isa 14:13-15 KJV -  For thou hast said in thine heart, I will ascend into heaven, I will exalt my throne above the stars of God: I will sit also upon the mount of the congregation, in the sides of the north:  I will ascend above the heights of the clouds; I will be like the most High.  Yet thou shalt be brought down to hell, to the sides of the pit.
The Venus Cycle and Biblical Gematria
The Isaiah 14:12 connection with the planet Venus is truly amazing. The mechanism of the metaphor Isaiah was trying to convey is identified; H1966 heylel translating directly to the celestial body we call Venus. One aspect of the Venusian orbit as observed from earth’s surface is that it occasionally appears to rise, then fall due to what is known as retrograde motion. It can occur when Venus catches up with the earth and passes at the conjunction. Venus can appear to rise above the morning horizon and then sink back below, thus the passage compares the king’s rise and fall to that of Heylel’s (Venus) apparent retrograde motion.
In one of the most amazing pieces of Biblical Gematria I’ve ever found is the combination of the two Hebrew words in this passage Heylel and Shachar. Whether in the original or later Hebrew interpretations, the Gematria values of Heylel (75) and Shachar (508) combine to a total value of 583. While that may seem like a random number, it is one of the most significant Gematria values that I know of. From morning rising to the next morning rising of the planet Venus (also conjunction to conjunction) averages 583 days!!! The Biblical Hebrew value of Venus+Morning is the same as the average Earth-Sun-Venus conjunction period of 583 days!! The Creator of the Universe and Author of the Bible can only be ONE AND THE SAME!!!!!
Kevin Heckle Sr