Usually I like to derive things from first principles before I go off and read about all the reasons my ideas were dumb. Every once in a while I come up with an idea that isn't dumb that I wouldn't have come up with by reading about them first. Generally people who are struggling to stay alive in dangerous conditions don't waste their time trying out crazy new ideas, which means they miss most of the good ones, too.

Thanks for the references! I wouldn't say I know a lot about this stuff. I know almost nothing.

Fire hazards are largely an artifact of building things out of combustible materials like wood. (Or polyisocyanurate foam.) Concrete, sheetrock, steel beams, and expanded sheet steel don't have fire hazards. Even so, it would probably be a good idea to have a refuge to escape to if a transformer or something caught on fire inside your arcology and started emitting toxic fumes.