How was Japanese animism referred to before 国家神道 (State Shinto) was created?

Question

Pre-Meiji:

• What was Japanese animism popularly called before 国家神道 (State Shinto) was created in the early Meiji period (19th century)? Prior to that, was the word 「神道」 a common term among the populace, or was it part of a jargon that the average Japanese person did not use in normal conversation or did not generally know of?
• How was Japanese animism (i.e. what might now be retroactively called 'proto-Shinto,' 'historical origins of Shinto,' or 'early Shinto') referred to before the word 「神道」 was coined? According to a book referenced in Wikipedia, the oldest recorded usage of the term (read as 「しんどう」) is as recent as the second half of the 6th century.
• How was Japanese animism referred to before the importation of the concept and word of 「宗教」 (religion), which happened in early Meiji? In other words, what were the beliefs/practices considered to be rather than religious practices?

Meiji and Onwards:

• How was 神道 referred to during early Meiji when the government was insisting that 国家神道 not be referred to as a "religion?"
• I have heard that 国家神道 adapts more from Chinese animism leading up to Meiji than from ancient Japanese animism. How are these differing roots described in Japanese (i.e. are there technical terms that differentiate Chinese-influenced Shinto from indigenous Shinto)?

Answer 1

To look for a time before the word "Shinto" was used, you must look back to the Asuka period, as the question suggests. At this time, the educated term for Japanese ritual was jingi 神祗. But I would caution against thinking of this as Shinto. The formation of Shinto as a nationwide ideal for ritual, practice, and teaching, did not happen in the classical period, even though there were already ritual traditions at Ise, Izumo, and other places. The Kojiki and Nihon Shoki, at that time, were simply history books, not sacred texts, and the kami were part of the Buddhist macrocosm.

We should instead think of jingi as the word for Japanese court ritual in contrast to Buddhist ritual. This contrast faded into the background with the end of the Heian period. In the medieval period there was shinbutsu-shūgō 神仏習合, free mixture of kami and buddhas, and identification of kami as avatars for boddhisatvas, and thus little need for a separate category. I think modern Shinto really began with Yoshida Shintō, a medieval attempt to construct a non-Buddhist theory of shrines, and developed apace in the Edo period.

In the Edo period, literate Japanese said that their country had "three teachings" 三教. This was a borrowing from Chinese civilization, where Confucianism, Buddhism, and Daoism existed alongside each other, sometimes in conflict and sometimes in harmony. In fact, back at the dawn of the Heian period the Japanese Buddhist genius Kūkai had written a book called Sangō Shiiki 『三教指帰』 that discussed these "three teachings"; the third was Daoism, even though there were no Daoists in Japan (that we know of), because he was endeavoring to compare it to Buddhism. Kūkai was responsible for putting the Japanese kami in a Buddhist cosmos.

But by the Edo period, the third teaching was no longer Daoism; it was already Shinto, or kami-no-michi. Shinto was recognized as having its own ritual tradition and style of practice, which was clearly not Chinese. This was due to the medieval tradition of commentary on the Nihon Shoki and Yoshida Shintō, as well as other pre-Edo ritual practices which are not so well-understood.

What happened to Edo period Shinto? You could write a book about this -- indeed, I plan to -- but to put it very simply, the Kokugaku school claimed that the existing schools were too private in character; that is to say, they were too religious. The goal of Kokugaku was to create a "national teaching", but simultaneously to create a public-facing teaching, something like what we would think of as "secular".

So what did ancient Japanese people call their animism? Likely nothing at all, since there was nothing to contrast it with.

Answer 2

Take into account that 1)Japanese people history in Japanese archipelago started very recently (at the earliest in the Yayoi period) and 2) they imported writing knowledge from China even more recently.

Since "Shinto" is a reading that stems from Chinese, most likely, in the same way as current "Nihon" was once read "Hi-no-moto", the original reading was "kami-no-michi" (this reading currently persists, even if not very common) or some archaic variant of it.

However, there's a possibility that Shinto was a "made-up" religion result of unifying original Japanese inhabitants' animism (which could be just one or several depending on the tribe, no records conserved on the topic) with whatever religion the Yamato settlers believed in, in which case the original name would still be Shindo/Jindo. It's not unusual for invading empires to merge their own religion with the ones of the people they invade (making their gods superior, of course), and Japanese Shinto shows traits that hint that it was exactly that case (they have both a main pantheon and a belief in nature gods, plus they have a clear division between "holier" Heaven gods and "less holy" Earth gods, that somehow existed before the youngest pair of Heaven gods gave birth to the land despite there being no Earth and them don't belonging to Heaven).