browndog, I sympathize, and you ask questions that aren't easy to solve....
So for her, and other searchers, they may be satisfied with the thin page, but they're also missing out on a much more in-depth page. It also contradicts the above guidelines which state...
You are likely also be dealing with who's reading what, and on what kind of device, under what type of conditons.
I think what's necessary is an organization and style that combines the best of both worlds... an article that can be initially skimmed, but which offers the main points up front if that's all a reader wants....
For reader with longer attention spans, or with more time, or reading under circumstances (say on mobile) where they might read the opening and skim the rest, the article should going on to offer the depth and detail for those wanting that more comprehensive material.
There are tricks in laying things out to grab the reader's attention along the way. I'd do a lot of research on "the inverted pyramid style", and I'd also read a range of wikipedia material and see how they do it. I'd also study Amazon, among other sites, to see their order of presentation.
Mobile material, eg, might be scrolled very quickly, then bookmarked for later if you've done it right. Make sure there is a way to email a reference from the mobile device to something you'll receive on your desktop.
But if you immediately hit your readers with all the details you've lovingly put together, you're going to lose too many of them.
Re not satisfying your checklist, when an algo ranks an inadequate page, it's because it grabbed at the best it could find. If you have good content without links, it's going to take a while to accumulate enough "freely given editorial links" to compete with some of the competing 800-lb gorillas... so you must publicize your content as well as create it... and be very patient... many months of patience... but don't push artificial link building, and don't fiddle with your pages in reaction to Google.
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To equidistant, to be quite honest, I read what you wrote with dismay. Somewhere, I think, you've been misinformed....
I guess the new SEO is to somehow convince Google that you are not doing any SEO. So instead of optimizing the title tags, file names and alt tags as you previously did, optimize them in such a way that it "appears" unoptimized.
I haven't seen anything that suggests doing that, at least not in Danny's article. If you are talking about old style keyword stuffing, even Google's guidelines caution against that, using some ludicrous examples of keyword stuffing, if I remember correctly... but the main point you need to realize is that those old techniques are no longer SEO. So, it's not a question of hiding that... it's a question of not relying on SEO bad practices from 15 years ago. They are no longer viable.
There was a time in old school SEO where some SEOs (and if they see this, they should know who they are) felt that onpage optimization should be so subtle that no one reading it could really say what you were optimizing for. They assumed that links with anchor text would do the rest. As a result, many SEOs now have sites with pages where I look at them and wonder what they are really about, as there's not enough relevant text on the page to establish a unifying theme... and as links become subject to greater scrutiny, there's maybe nothing left... and some really good material doesn't rank because Google-the-machine isn't psychic.
I see that Danny isn't saying, keep things secret... he's saying, send us a clear message. But it's no longer about scattered "LSI" keywords dropped into a page.... That's nonsense, and those really aren't actual LSI keywords anyway...
I always do make sure I use enough contextual language so we have several ways of triangulating the vocabulary and the theme. It is about ideas, now. I do try to include keywords too, because I don't think that Google is quite at the point of "understanding" everything without them, and it's about good writing.
Note too that Google does not get humor, irony, or many figures of speech.