I figure that the cabins squeezed between other "working" parts of the ship falls in line with the idea of a packed ship of equipment with crew squeezed in. It reminds me alot of old navy ships that had bunk beds next to equipment.
The use of the briefing room studio set as a room of "environmental engineering" could suggest that, but "Wink of an Eye" would be the only episode where they put the set to engineering use.
I'm not sure "3" could be third-class as it does look very similar to other cabins. We don't get a good look into the second area though. Is it a work area like Rand's cabin? Or a second bed and he has a roommate?
I absolutely hope so. The office desks use up a lot of valuable space so ideally only senior officers or the captain's yeoman should
be able to use them.
Oh, these OFFICERS QUARTERS direction signs.
How many different ones do we have?
The one from "Day of the Dove" read " 6F-24 66-38
", others read " 6F - 53 77-99 ".
Apparently these show up on almost every deck of the saucer. Either you have officers quarters on all crew decks or stairways or the like leading to these and on other decks. I find it increasingly difficult to rationalize these for the deck plans.