Mashy

If this game is meant to be mature then the addition of romance/sex seems essential. The addition of prostitution could tie well into character development. I'm not advocating this game turning into an interactive Mills and Boon but rather giving the player (or companions) the option of interacting with the world in this way could add depth to how the world interacts with you. You could get an STD and have to deal with it somehow, your companion the beserker could be constantly hounding you to take the party to whore house or mocking you if you're a virgin. There will undoubtedly be religion within the game and this addition could effect any interaction you have with them. I resent that often in games, romance is possible regardless of the character of both parties. Companions for who there is a possible relationship should each have their ideal partner and you should only be able to start a relationship with them if you fit some loose requirements. It always struck me as silly that you can act one way in the game world and sweet talk a potential partner with what is directly opposed to how you act. You could convince someone you were an innocent and reluctant fighter while brandishing your sword, soaked in the blood of local law enforcement.