this is all correct to the best of my understanding. i'm going to add some supplemental information to your post; please don't read these as arguments against your points, but as more information relating to them.
> Richard Hayes, in a book titled "The Moral Vision of the New Testament" (p. 382) says, "This word is not found in any extant Greek text earlier than 1 Corinthians. Robin Scroggs has shown that it is a translation of the Hebrew mishkav zakur (“lying with a male”), derived directly from Lev. 18.22 and 20.13
more specifically, an adoption of language from the LXX translations of those verses. consider:
וְאֶ֨ת־זָכָ֔ר לֹ֥א תִשְׁכַּ֖ב מִשְׁכְּבֵ֣י אִשָּׁ֑ה תֹּועֵבָ֖ה הִֽוא
the bolded words here are "zakar" (first on the right) and "mishkav" (second on the left, a conjugation of shakav, lay). they're actually parts of separate phrases, but it's clear they've read the implications here and formed a new phrase in interpretation. the corresponding words in the septuagint are:
καὶ μετὰ ἄρσενος οὐ κοιμηθήσῃ κοίτην γυναικός βδέλυγμα γάρ ἐστιν
these words are (left to right) "arsenos" and "koiten". this the greek of 1 cor 5:9:
ἢ οὐκ οἴδατε ὅτι ἄδικοι θεοῦ βασιλείαν οὐ κληρονομήσουσιν μὴ πλανᾶσθε οὔτε πόρνοι οὔτε εἰδωλολάτραι οὔτε μοιχοὶ οὔτε μαλακοὶ οὔτε ἀρσενοκοῖται
"aresenokoitai". so this is probably where paul got the phrase.
> Therefore the word does include pederasty and homosexual rape, but that's not its only meaning.
for the similar verse in lev 20:13, sanhedrin 54a:29 states:
GEMARA: From where do we derive the prohibition and punishment for homosexual intercourse with a male? It is as the Sages taught in a baraita with regard to the verse: “And if a man lies with a male as with a woman, both of them have committed an abomination; they shall be put to death, their blood shall be upon them” (Leviticus 20:13):** The word “man” excludes a minor boy. The phrase “lies with a male” is referring to any male, whether he is an adult man or whether he is a minor boy.** The phrase “as with a woman [mishkevei isha],” referring to lying with a woman, appears in the plural. The verse teaches you that there are two manners of lying with a woman for which one who engages in intercourse with a woman forbidden to him is punished, vaginal and anal intercourse.