In my opinion, outside of the usual books like the Kojiki, Nihongi, and some fudoki translated into English, you won't find any collection. This is an interesting question to which I don't have a definitive answer for "why." My theory is based around this component of your question-

I am hoping there are further details available which ideally could account for a broad cosmology, with internal politics, drama, as well as localized/regional lore, and perhaps also evolving, historically-informed adaptations of the foundational mythology

Unlike Greek mythology, the cosmology of Japan is taken to be part of Japan's history, itself. But that history is very recent, roughly 5-9th centuries AD. The emergence of Japan as a state is based on modernity, which makes a complex cosmology with deities a bit of a tough pill to swallow. Furthermore, Japan had already been heavily influenced by China and Korea politics for centuries at that point in time, which played its own part in the divine aspects of Japan's early years- Daoism, Confucianism, and ultimately Buddhism.

See, what we think of as Shinto and kami as "gods" is a relatively modern phenomenon. I wrote about this recently in another answer. To sum up, in the early years of Japan as its own state (versus a collection of fiefdoms all sending envoys to China), Buddhism and Daoism shaped kami as we know it to the point where Shinto scholar Mark Teeuwen points out the very term shinto 神道 was the Chinese Buddhist term shendao and was really read kami no michi 神ノ道 or "path of the kami." This evolves in the 11th century to the first records of kami as honji suijaku 本地垂迹, suijaku 垂迹 ("manifested forms") of buddhist honji 本地 ("original states"). Kami were local manifestations of the abstract buddhas.

And this is often times how they were used in stories. Instead of Dainichi the enlightened buddha, you might have Amaterasu making an appearance. But the two were often times analogous, and would continue to be through the Edo era when a more formal "Shinto" takes shape. Even in that formal structure, the thousands of localized kami were still thought of in relation to Buddhism, though now they were the source of cosmic Truth vs the buddhist teachings. That was more a matter of politics than anything.

Cosmic politics matched local politics in this regard. I'll point another answer from that same Shinto thread above that I wrote. Kami and Buddha could co-exist, be exiled, come back, morph, etc depending on the shrine's clientele. As Kuroda Toshio put it, "shrines and shrine-based practice [pre-Meiji] was nothing more than Buddhism's 'secular face'" - which meant the locals with power controled the rituals.

This culminated in Edo when the Bakufu sought to control religious practictioners deemed a danger to society. Local shrines were compelled to place themselves under authority of larger templates with specific duties, for example. This effectively killed a lot of small local kami, but remember this is the modern era where cosmology plays a much diminished role.

But I think the main point for why there are no collected tales is because such tales didn't really exist, not like we see in the Greek mythos. Zeus, Apollo, Aphrodite, these are divine entities with human form, structure, emotion, and stories that result from such qualities. Japan's cosmology was hugely abstract, given form in relation to Buddhism, with what stories we have outside of the various historical accounts being just that: buddhist lessons with non-buddhist entities. You won't find a tale about the tree kami of Ise plotting against the tree kami of Izumo, for example, because neither was something concrete capable of "plotting." And kami as manifestations of the buddha wouldn't have drama or internal politics either given that all buddhas are considered the same as their core. The wrathful Fudo Myo, for example, is the same as the enlightened Dainichi Nyorai; they can't plot against each other because they are the same entity- you, me, and every other human at their point on the path to enlightenment.

Sorry for the late response on this, doubly sorry what you're looking for doesn't exist. If you really want to understand old Shinto... study Japanese Buddhism and political history IMO :)