I am currently looking for ways to raise reputation in these two areas not for the achievement mind you but wondering why the reputation stats are even posted on your character sheet if they can not be changed. Perhaps this is a indication that in the future with a DLC that it will be. The Mill is something that i do not even know what it pertains to. I know I have done all the quests with the millers to include a quest with a Miller to deliver the Captured Cuman to Rattay. Perhaps a Developer or a Q and A person at Warhorse could respond or if any of you other players have managed to move reputation there let me know.