Fascism is a top-down ideology. It happens when capitalists feel that ordinary people are close to demanding a more equitable society, and they use it to divide society and assert their own authority. It is often described as a petit-bourgoise ideology because that is where the fascist capitalists find the most fertile ground - people who used to be able to afford a good life, but who can't anymore. Of course, the irony is that the reason they can't afford a good life is because the capitalists are siphoning off more and more of the wealth.

I think (the reason to what are you describing, and that I agree with) it's more to do with how in any democracy needs constant work from the people (not once evey few years a popularity contest) & how it's always, at all times naturally threatened by individuals seeking power. If you one too many times don't act in time you get an autocratic gov (that it might take a lot more than voting to defeat).

Basically oblivious demos vs the rich class radicalising political/pubic systems (deregulation etc) so serve their short-term financial gain.

I recently watched this NOVA bit about power struggles in Athens (something I knew about prob 30 years ago):
dailymotion.com/xa7xuec

not a bug, a feature

I think you are mistaken here. While hardship is helping them, it is by no means essential for them to be successful. I think Austria is a good example to prove the case. It was one of the first countries to see the rise of what is nowadays called alt-right, back when it was still very taboo in most European countries. The "Alt-right" has not really changed in Austria but it has become much rarer to be criticized for it or being painted as a country full of Nazis, at least nowadays only hypocrites are still doing that.

Given that we have decades of track record in Austria and at least 2 boom and bust cycles, it draws a clear picture that the ability of "people who own their own homes, who can support whole family with a single job." has a fairly poor correlation with the ups and downs of the FPÖ.

It has much more to do with anti-migration sentiment, independently from actual migration developments (as the FPÖ has been also successful with this in times of relatively low migration) and with a general and not really concrete fear of the future. The FPÖ has imploded twice, both times it had nothing to do with what others did, no matter if isolating the FPÖ, countering its points, trying to copy it, trying to address its points with more moderation or whatever. No, what really hit the FPÖ was its own corruption and lack of integrity but only when the pile of shame got so big that the the country lost billions over it or it got so bad that not even shouting "but the nasty foreigners" could redirect the debate. In both cases, FPÖ voters remembered the scandals for about one election, afterwards it was like it never happened and we were back to step 1.

Of course, nowadays we see how life is rather getting harder, and that does of course help populists that are simply promising whatever anyone wants to hear, but like I said, populists don't require that, they merely benefit from it.