I have some idea, as i really liked the concept of your game.
Most of them would make your "merchant" look more like a bad person.... but is that a problem?
An option to place traps somewhere, creating you new clients (bit immoral, but money is money) like a new destination, where you can choose what you place in a local dungeon
the other one (coming from the trap sidequest) is to keep those girls as your slaves / or train them to sell them at a dock or port, you could have a barn/warehouse full with captured bound girls waiting for you to play or sell them for big money (maybe with some kind of risk, so its not op)
The other one is accidental "plays" with clients coming to you, as i said before, who has no money, can pay with sex, or you can play with her in a minigame, like if you fail a minigame, the girl get vibed by the enchant, or a dwaren dildo starts up, so if you fail, x times the customer will have a GREAT time, if you get it x times the chastity drops, but you get another "reward"