Thank you for this much needed counterbalance to those who misrepresent biblical teaching, either deliberately or through ignorance. Such misrepresentation harms the religious and non-religious alike. The religious are led to believe something not supported by text, which ultimately leads to acts and policies that violate both the letter and the spirit of the text. The religious are also seen as fools for these absurdly harmful acts and policies. The non-religious bear the brunt of judgement and worse handed out by either well-intentioned or ill-intentioned but sadly misinformed zealots.
A quick note on the idolatrous practices part of you presentation. In my reading on this subject I have come across numerous references to both male and female cultic prostitution as a form of worship in the idolatrous religions of the early biblical era. This, along with the placement of the passages in question (in the middle of instruction on ritual practice) and the fact that, as you point out, all of the other sexual acts surrounding the passages were common to other idolatrous religions, makes it clear to me that whatever is being proscribed here has to do with idolatrous practice, a big enough issue to take up nearly one-third of the ten commandments. This cannot be as clearly represented as a prohibition on private sexual relations between people.
Bottom line, there are far more complex and nuanced conclusions to be drawn from these two troublesome texts than the simple gloss placed on them in common translations. You have done a good job laying out some of the discussion surrounding them. I can only hope that this helps others to read the text more closely.