If anyone honestly believes that having a slave or prisoner would be in bad taste... well c'mon. This game encourages you to beat a priest into submission with a rusty mace... twice. And that's probably the least heinous thing your character could do. With ease, we can massacre entire cities, or murder a man to steal his wife (and store). Previous games had slaves present in houses owned by every character but the player, and you even had a slave of your own in DLC content for Oblivion (eh.. kinda). So I don't think it would be any moral stretch for gamesas. Not only that, but (sadistic as it might sound) I think it would be an assload of fun.
So, please, I don't really think that we should object to the idea of prisoners and slaves and dungeons for the player on some sort of ethical or politically correct reason. Shadiness has always been something that TES allows the player to embrace, and the assassin guilds, stories, and quests have become darker and darker with each iteration.
I should think quite the opposite actually. The players of a TES game should rightly be mature enough by this point to handle having a slave of their own.
So, how about it?