Interesting read. Some unsorted toughts about it:
I'll try it tonight I think... but I thought somewhat more about it, when I want to make booze available for my "staff" wouldn't it be that locked away dwarves which are thirsty would try to reach the booze eternally and then die of thirst, even when they're standing right at a well? Or is it that they only go for things that are within possible reach?
I think a own room which is staffed like that would cause too many positive thoughts, which is contraproductive for the challenge, there should be no happy prisoners. And the whole individual cell thing is too modern for my taste. People should simply get thrown in sleeping barracks, maybe parted at sex or profession etc.. I think it would be more like a forced labor camp (which IMO fits more to the dwarven mindset) than a modern day prison. There should be a shortage of beds.
You could also make a dungeon where there is practically no physical connection to the pocket fortress above. Prison staff could just dump food etc. in... (with the typical shortages and collection of assorted spoiled uneatable stuff) doors are lockable with levers, there could be a room where finished goods are brought too regularly, and which is absolutely locked otherwise, to make sure that there is no connection to the world outside. It could also maybe make meeting zones for prisoners and staff parted from each other possible. The Leader should also be a exceptional good record keeper, all in all.. that's his job. Could it happen that dwarves simply elect another? Is this somehow to change?
There should be no economy, it just wouldn't make much sense.
This is all dependent from the pathfinding through... especially from prisoner dwarves not permanently trying to path to the staff fortress above for food, booze etc.
I remember in old 2d versions, where the pathfinding was very pissed off at locked doors and they would cause severe lags and odd pathfinding errors. I know that toady has enhanced that somewhat, but I don't know for certain if it suffices for this challenge.