That's not quite what that article said though. The article said, “We are not bound by these commands" (and that particular statement was based on making the point that this specific passage is about ceremonial uncleanness). That's different than a blanket statement about "none of the commands being relevant". There were commands in those chapters about not lying, not being unjust and treating people with favoritism---those things certainly are relevant today.
When you say such things as :
the chapter following (still part of the Holiness Code) has this passage (as a continuation
I thought you were applying it to the whole section. What is the significance of this holiness code to you? Why mention it? It seems a misnomer to me because they were to be holy in all their actions, and all the law referenced this.
You seem to be making sub-categories for the commands.....and I'm of the belief that it all goes together.
As I said in the other thread as moral, ritual, laws etc., were part of one law. However the source you pointed to was talking about this holiness code which they see starting at one point and going to another point. And it talked about how some commands do not deal with ethical or moral requirements. So I am responding the to the source you quoted which is dividing them into either moral or ritual commands. Why would you quote a source that has that view if that is not what you are trying to say?
In any case, if you acknowledge moral commands in this section, then we cannot simply dismiss these commands alongside of Sabbath keeping, clean and unclean foods, etc. as you earlier referenced, without examining whether they really are dealing just with ritual laws for Israel.
Since the nations before were judged by doing them, it is clear the moral principle behind these specific commands go beyond Israel.
There's a thread (or theme) of purity all through these chapters (a very high standard of purity--things like not wearing mixed fabric, not eating pork, careful instructions for food used in sacrifices, trimming of beards, etc). Not everything pertains to sexuality.
I'm not even convinced-at the moment- that the offense in Lev 18:22 even has to do with sex. It could just mean that the men are lying on the couches/beds that are meant for women (and that would be impure)....much like the mixing of seeds in a field or wearing mixed fabric clothing.
Nor did I indicate everything in the section pertains to sexuality. And of course, the whole of the law dealt with purity as I posted in the other thread, because God dwelt in their midst. However, it is not limited just to those chapters. The chapter before, 16 spells out the method for dealing with all the sins and impurity, chapter 11 deals with unclean animals, etc. so it seems rather arbitrary for them to put the section that they did as a holiness code.
However, as to the sexual nature of it, it is in the same chapter and close context with other improper sexual relations, and the nations before this were cast out of the land for it. Are you suggesting the prior inhabitants were cast out for two men reclining on the wrong bed when they were not warned of this?
In particular it is in close connection to verse 23, and seems parallel with it. It seems quite unlikely vs 23 is prohibiting sleeping in the area for animals, especially as women are forbidden to present themselves for the occasion and the word used is the same as that for copulation between different kinds of animals in chapter 19. The context is sexual.
Lev 18:22 You shall not lie with a male as with a woman; it is an abomination.
Lev 18:23 And you shall not lie with any animal and so make yourself unclean with it, neither shall any woman give herself to an animal to lie with it: it is perversion. 
