My studies show that 10 foot decks (with a few inches between) done exactly how Jefferies designed it works fine. But if you think you have to have two feet between decks and a three to five foot thick hull... use something bigger.
How thick is the skin according to your estimates and figures?
Considering that the corridors have walls that are more than 2 feet thick and were shown to house all the stuff that people assume must be in the floors, what other reason would you need more than a couple inches between decks?
I never thought about much being housed in the corridor-walls. Wouldn't that be a problem if a high intensity phaser-blast hits them?
Wha? Who's Nero?
I'm pretty sure you don't mean the psychopathic Emperor of Rome who blowtorched part of his city, then blamed Christians and brutally killed them...