I believe there were Braille editions of comics like Astérix or whatever but no idea how the layout would work in relation to a regular Braille book since it's a highly visual medium.

There are two youtube channels you should check out, the Comicstorian and Comics explained, One produces audio dramas of major comic titles, and one discusses the stories in comic books in the same way that a friend might relate anecdotes, neither is a perfect re-creation of the comic book experience but for somebody who loved comics when he could still read them, it is a lot better than nothing

Not that I’m aware of, sadly, there used to be this large print magazine that my ISTV got me and they had short large print comics but I don’t know if they’re still in print or even suitable. Marvel has one Braille comic I think due to they’re Hero Project.

There is graphic audio. They do audio books of a major comic story like civil war. They are fully acted with different voice actors and sound effects. Not a Braille book but worth a try. Some are free to rent on hoopla if your library uses it.

No, but I do read a lot of manga. Not in book form, I can never read stuff that small as a legally blind person. But, most manga is online, so by browsing it and being able to zoom in on it from a big computer screen, I am able to make out the images and enjoy it. Otherwise, I'll just get Braille books or audio

I recently read an interview with Chad Allen who has created a comic book for blind people called Unseen. He's someone who lost his sight and missed comic books, so has written his own own audio one https://www.theguardian.com/books/2019/sep/18/we-see-with-the-brain-creating-comic-book-for-blind-people-chad-allen-unseen

There was also a guy who developed a tactile comic book using a combination of Braille and embossing: https://www.hallo.pm/life/

I read manga and graphic novels on my tablet with the Kindle app, if that helps

Not that I’ve ever heard of. Sometimes people will do an audio version of web comics like Homestuck where they read it out loud, or there’s a sort of novelised version that just describes the pictures. But I’ve only seen it with web comics. The one thing like that I saw with a mainstream comic got taken down by the publishers I think. Really a shame. I miss comics. At least with manga you can wait for the anime to come out (and then wait more for an English dub and a friend to describe the action to you).