Well, let's see. The aim of the game, inasmuch as one exists, is to build. You seem to have taken up the position for the purposes of this paper that the player is another, invisible dwarf tasked with co-ordinating the fortress construction, so I would say that the 'duties' of the player are set out in the starting text- provide for your dwarfs by any means at your disposal, with the implied aim of building the outpost into a thriving metropolis and ultimately attracting the king. However, the player does not have to embrace the only consequence, should they choose not to, as that those things won't happen. Get your dwarves killed and you 'lose', or get no immigrants, or simply don't see the king, and higher nobility, etc etc... all game consequences, not dwarf society punishing the player.
Dwarves, on the other hand, have laws to keep them in line. The crimes we know about tend to involve destuction, either of people or property, and also for being insuffficiently industrious, as judged by the Nobles. You might look at the duties of the nobles... I understand some of them used to provide the player with benefits, but now they're mostly an encumbrance to the player so perhaps you could explore player attitudes to them as a result.
Dwarf virtues... if you agree that their overall purpose is to build, the average dwarf's virtues are things like diligence, obedience, and skill. It's worth noting that individual dwarf personalities do not always include these things. Perhaps also look at the privileges which are afforded to legendary dwarves as evidence that skill is seen as a virtue?
Rights... that's a tough one. As I mentioned, the player can do anything they want while the dwarves are subject to laws, which raises interesting questions about whether the player and their dwarves have anything in common and whether player actions can violate dwarves' rights- if every dwarf has a right to life and limb, what about the player who doesn't mind killing a miner to set off that cave-in? You could argue that the player has a hand in determining what rights and privileges their dwarves have. It's possible to play as though every dwarf has a right to a bedroom of a certain siize, for example, and reward dwarves for importance, bravery or anything else you choose with large rooms, art, furniture, etc. It's also possible to deny your dwarves a place to sleep at all.
Hope that gives you something to think about and isn't all futile rambling- I haven't studied ethics or philosophy, but those are the points that seem relevant to me.