"I think myths often (always?) most embody those things that a culture *can't* articulate and often doesn't even wholly enact." - well, I might say the post-Enlightenment Faustian myths were certainly never better-enacted by any *other* society!

The evidence on Etruscans I heard about is supposedly from archaeology about them, but I don't know details; I still need to check those differences between depictions of sex, and, who'da thunk, romance! (Then again, it's called "ROMANce", isn't it?)

"Maybe nuance about morality is the norm and lack thereof is the weird exception?" - based on not-much knowledge, it appears to me that later Zoroastrian (don't know about early) and Abrahamic cultures tend to be rigidly moralizing, Indo-European myths tend to more moral nuance, and a lot of other myth seems light on morality to me?