Woah, woah, there. What's with all this thought and attention to details?

Hell, they connect to hell.

Is there an in-universe explanation for how the Discworld has an atmosphere?

Now John was clothed with camel’s hair and wore a leather belt around his waist and ate locusts and wild honey

It's the land of the dead but they did actually know about oil trapped in rock then, shale oil extraction specifically is first referenced in the 10th century by an Arab researcher.

Make sure it's bigger.

It's literally what happens in the story of Noah.

where does the air go?

Hmm. They had bellows, and knew what air is, so that's actually a period-appropriate question. Maybe Sheol can be pressurised, or maybe Noah just didn't notice the air getting thicker.

The rest is just a version of "what's outside the universe", which applies to real cosmology too.

The firmament did open and leak. That's why we don't live as long as Methusaleh anymore, silly.

Well considering the main creation story in other nearby cultures at the time also say the world was originally all water, I’d imagine it isn’t so much symbolism as it is the fact that water falls from the sky occasionally and typically looks blue.

The Enūma Eliš mentions that originally there was just water. Much like the creation story in Genesis the gods eventually separate the waters and expose land. Also curiously, the story is recorded across seven tablets and has a few more similarities with Genesis and other aspects of Judaism like man being a fallen creature (though due to man being made from the corpse of an evil god or because the gods were worried, not due to women lol)

Also, the oldest creation story I’m aware of is The Sumerian Creation Myth which also references the “cosmic freshwater ocean” and says man lives in the lower region of this ocean. The noise of humanity annoys the main god so he sends the flood from the upper ocean. But one god warns a man of this so the man builds a boat and fills it with animals. Remind you of any bible story?

Point is that even the Torah is a likely derivative work combining more ancient myths from other cultures. Because the original cultures reference the waters more as an actual physical ocean in a non-symbolic way, Id say the Bible story was meant to be literal. Almost all symbolism derived from the stories therein is likely interpretation only.

I suppose the Hebrew scholars collecting these stories could have viewed them in a more symbolic way, but the first text I referenced is a few years younger than the Torah and still references oceans in a more physical way. So, I’d imagine their meanings were initially similar.

Ok, but clouds, damns, waters above, or sky oceans - why would anyone write down the sun & stars being in front of the clouds/sky river?

Wouldn't ppl reading that just like, you know, look up & go 'well that's not what I see, what else here is bs'?

Will you accept Ted Chiang?

https://en.m.wikipedia.org/wiki/Tower_of_Babylon_(story)

Found the full text https://myenglishhomework.com/wp-content/uploads/2021/03/tower_of_babylon_-_ted_chiang.pdf

I think an open world videogame with this sort of world would be really neat.

I mean, this is already basically how videogames work, but it could be made diagetic and stylized like this.

It should be fine. The copyright expired some thousand years ago.