I don't think "Lucifer" in Is. 14:12 was actually intended as a "name" for the devil. "Lucifer" is actually just a transliteration of the Latin word for "morning star" - the KJV translators just duplicated the term used in the Latin Vulgate because the Hebrew word is used only once in the Old Testament and they didn't know what to make of it. Jerome, the translator of the Vulgate, knew Hebrew better than the KJV translators, but even he was uncertain about the meaning of the Hebrew word. But at least he made an attempt at a translation. This link helps explain.
https://bible.org/article/lucifer-devil ... anslations
The word means ‘constellations’ or ‘crowns’ (modern translators are not sure, though ‘constellations’ is usually preferred). The fact that Jerome recognized that at least the מזרות probably referred to stars is far better than the KJV translators did by leaving the word completely untranslated.
That said, I have two things to add:
1) I don't mind calling the devil "Lucifer", especially when referring to his pre-fall existence; we don't know what his actual name was, but it could have been Lucifer, and we all know what it means when someone uses the name.
2) While I doubt Is. 14:12 intended it as the devil's proper name, I do believe the devil is partly in view here. I think this is one of the double-fulfillment prophecies. In the short term, the prophecy refers to the Babylonian king; but verses 12-15 seem to go beyond the description of a mortal king. So the secondary fulfillment is in the pride and fall of the devil, whom the king of Babylon is a type of. Also, Luke 10:18 (which you mentioned) and Rev. 9:1 seem to connect to this passage. Plus, some in the early church - Tertullian, Origen, and Augustine - interpreted it as referring to Antichrist. So I think this view seems reasonable solid based on the sense of the passage itself, plus interpreting scripture with other scripture, plus tradition.
The same goes for the anointed cherub in Ezekiel 28 - I see that as a double fulfillment also. It goes far beyond the description of a mere mortal far more than the Isaiah passage, and just makes more sense as a double fulfillment, in which Ezekiel is saying the king of Tyre is a type of Satan.