"The politics of the people being discussed (at the intersection of alt-right and lifestyle) are made fairly clear in the terms used. As for whether those people constitute the majority of the "movement" who can say - though I'll note that you also provide no numbers for assessing this in likeness of the author."
First off, I think it's good that we ALL remember that most people are just not that all interested in politics. There are no shortage of studies showing that a substantial majority of Americans pay little attention to politics except in the period between nomination and election every four years. (This comes as a constant surprise to the politics-obsessed, who assume that everyone is as obsessed as they are.)
So, the first objection I would raise is that if a person wants to tie a traditionalist family movement to politics, it's on that person to prove that they are motivated by politics, because most Americans aren't.
To that end, I'd point out that it seems intuitively obvious (speaking as a traditionalist Muslim, and knowing plenty of traditionalist Christians) that the motivating factor behind such movements, if other than just nostalgia, is religion.
Despite this rather obvious matter, the OP never considers religion at all; the word does not even appear in her article. She goes directly to race (and then politics) with nary thought to the more obvious causality of religion, which leads me to conclude that she was looking for evidence to back up a narrative, rather than let the narrative develop from the evidence.
"What we can do is, in thinking about the implications here, assess "traditional" living directly and why it is of some concern, given its inherent contradictions and loose definitions."
"The hidden requirement for "traditional living" seems to be that it depended on - as displayed prominently in the artwork - abundance."
Without objection. In the days of 50's television, it seemed that the wives could all stay home and all lived comfortably on Father's mid-management job at some bank; the fathers were never depicted as CEO's. And we also know that today, the median house, median car, and median college education consumes a far larger % of the median income than it did in the 50's. So your observation is spot on. Ergo, I suspect that most couples choosing to live like this are making decisions to live quite frugally.
But, now that you've raised the spectre of the illustrations used by the OP.....did Norman Rockwell paint pictures of (white) family life because he was a racist, or because that's what he knew? (Or, do you not see the distinction between the two?)
"To be quick: To use the words these people might use, can one build a truly great society off of cultural modes that can only be afforded by a shrinking fraction of Americans?"
No, but nobody is trying to coerce individuals into this lifestyle, so I view the question as moot. It's a lifestyle choice. So, the questions you ask in that same paragraph I will have to view, sorry, as irrelevant. If a couple chooses that lifestyle, it is up to them to make whatever financial decisions are required to enable it.
"Should we take more seriously the concerns of the proto-feminists who lived back then who - in no small number - abhorred a life of total dependence on their husbands, without whose approval they at times could not seek work or make financial transactions?"
I don't see how it's any of their business what choices other people freely make. I know that they WANT to make it their business (we have rapidly become a society of control freaks, in my opinion, but that’s an entirely different essay), but it’s not.
"Wouldn't traditional living attract those interested in having some approximation of that kind of power over their partner's life?"
Yes, plus also those who want to live in a relationship where they relinquish that kind of power to their partner.
"And what would be the risk that, within that relationship, coercive means might be used to push someone away from having that control - even around their own finances - as part of entrenching the totality of that traditional relationship?"
Sure, there's risk there (although you're starting to make this sound like some sort of "Total Power Exchange" favored by some in the BDSM community). :-)
"If the core of this .... what are the risks?"
Again, of course there is risk. But are we now in the habit of dictating to adults how they must run their lives?
"That's just the beginning of what my amateur analysis can think of for this. That's not even including the original author's concern, that the mix of far-right views (which I imagine even anti-SJWs can take issue with, esp. given that race politics is a kind of identity politics) and these more public, presumably more permanent social relations can be dangerous. I don't particularly agree with how she seems to label the issue as their "denial of racism" (I think if someone starts tweeting about foreign invasions and a need for "white solidarity", they've already adopted "racism" as a kind of crucial tool for defense in their eyes) but I would be more concerned with the broader conspiracy that often afflicts the far-right - correlating outcomes and assigning causes that are often personalized down to individual antagonism against someone else’s individual choices - and how these relationships could be put together as vehicles for proliferating those notions among themselves and potentially their children."
To be honest, I'm not sure how to process all that. There are always going to be women who want to raise children and keep a home more than they want a career, and there are always going to be men looking for that sort of woman. To repeat from above, I don't see any racist issue here, because those sorts of women and men are going to be found in all racial and ethnic subcategories --- if there is any external communal "force" encouraging them, it would be religious, not political.
3. For the broader debate on parenting and life styles, live and let live is a fair standard to live by: Side note, so long as those you "let live" intend to let you do the same.
Actually (3) could have been the entire response to the OP's article. :-)