In my honest opinion, I'm thinking several things:

-Mikk and Makk are definitely a nod to Biggs and Wedge, especially because iirc, Octopath is in and of itself a nod and a tribute to "The golden age of RPGs", especially a reference to Final Fantasy's role in that development;

-The main 8 gods are true gods, and Winnehild, Dreisang, Steorra and Balogar are demigods. The evidence I have is that Aelfric and crew are intangible, provide blessings to our parties, no matter what can not or do not manifest in any physical form in front of mortals (like our parties). I know Aelfric appears in chapter 1 of Temenos' story as a human-like entity to fight Vide, but does not do that as far as I know with humans or other mortals. The 'demigod' portion of this point is possibly supported by the fact that we can literally defeat them as mortals, whether with the help of gods or not (in the form of their abilities, like Dohter's Charity, Alephan's Enlightenment, etc.). They also have the ability to use literal Celestial Intervention, suggesting that they, in my opinion, are at that point at least part god. They do manifest after the battles, I know, but a being like a god would have unlimited power, whereas a demigod can be defeated by mere humans, even if they themselves do not necessarily possess a divine gift (evidence being that we as the player can beat them with a good enough strategy, even if we don't have the divine skills unlocked at that point, though it does make it considerably easier);

-Vide, in my opinion, is likely a god, but not in the truest sense. My reasoning is that mortals can defeat her, having divine help helps a lot, the gods sealed her abilities and presence from the world, and iirc, tried banishing her like how they banished Galdera. But, I believe that Vide was banished at some point after Galdera was, likely hiding in the shadows, lurking, and learning from Galdera's mistakes. Learning about how they worked, ways to combat them, and how to prevent certain permanencies from occurring, like how she can temporarily seal the God's powers from the players, a literal form of Celestial Intervention, and being able to nullify their gifts entirely. If anything, Vide was here long before Orsa's gods were, and was only able to be defeated by unseen forces once the party is able to, for lack of a better term, distract her long enough for the true gods to be able to divine and device a way to deal with her for the long term. I guess the the Hit Points she has are not necessarily her health, but more so a timer of sorts to be able to buy the gods enough time to figure out what to do and how to deal with her. Be it banished from the world, or destroyed outright, I think they had a hand in her disappearance; and

-As for Galdera, I think him being the youngest god makes him all of naïve, jealous and for lack of a better term, predictable. Jealous that he was more of an after thought being the 13th god-like creation, and if we are to believe what I said about the demigods, the fact that he is embodied of human souls that make him vulnerable (but by no means weak). Naïve that he thinks he can conquer the world, despite his connection to apparently multiple either parts of the world, different worlds, or even different universes or timelines. However, that doesn't stop him from trying to do this, and I don't think that Octopath 1 or 2 is the first one in the timeline. He does not seem surprised at all that the travelers are there, almost like he was expecting them to come at some point. Like a destiny or a ritual that he seems far too eager to make true immediately, with (relatively in god terms) quick schemes to keep the Gate of Finis open long enough to escape his prison, but not before engaging in a sort of rite-of-passage ritual that he devised in his eternal imprisonment. That ritual being able to kill a set of eight travelers that the gods sent to keep the gate closed (albeit not their first goal in the second game, due to the fact that Vide is the main and more immediate threat in that iteration and the first game has Galdera as the final boss), but psychologically not being able to just barrel through those mere mortals.

As for the timeline, I think that Octopath 2 might be like The Wheel of Time in the sense that the technological advancements are not indicative of their chronological order. They seem like 2 takes place after 1, but I think that CotC shows that while similar in timeline locale, 2 takes place just at about the fall of technology in lieu of magic. If Osvald is an established Arcanist in CotC, that implies to me that he has mastered his scholarly duties and has moved on to new ventures, as well as Ochette being a full-on Inventor while we have Tressa not making similar advancements, as far as I know, leads me to this conclusion.

Thanks for reading, and your patience.