I agree strongly with 1), with the addition that another one happened in the modern era when engineering prowess, military strength, and highly versatile, effectively truth-seeking science and philosophy finally coincided in Europe and Asia.

I suspect that if neither the singularity nor a disaster occurs, there is likely to be a different huge shift, probably focused around a resurgence in the power-and-control super-science that defined Victorian through Space Age technological advancement, or alternatively in some form of social sphere.

I'd also add that barring either a singularity, or the adoptation of a massive amount of AI and automation in society, the rate which completely shocks the most privileged and tech-savvy members of society in one lifetime is probably the limiting factor in technological development rate. (My view of Kurzweil is that he ignores this, which leads to absurdities such as sub-AI tech developing faster than humans can integrate information and design new stuff)

Montaigne (from the Renaissance era) suggests that hunter-gatherers or early agriculturalists were indeed pretty shocked by even French Renaissance era society: they found the acceptance of social hierarchy unthinkable and also (this seems more like a specific cultural thing) were confused by fear of death.