itch.io

Character ideas first as I initially misread your post. Tavern could go cow theme, Training I would do a amazon with skimpy or bikini armor that becomes chastity and bondage gear. I would put the ponygirls on the farm and put a stagecoach driver with a riding crop that gets swapped to dom gear and a whip at the stagecoach. 

As for buildings themselves, the tavern or barracks could gain red lights and curtains shifting to look more brothel like (its it feels like it would look better on the barracks icon than the tavern) In front of tavern put a waitress with sign as a sign girl, her replaced with a bunny girl or dancer with a alt sign. The Mental word could swap the star for a womb tattoo crest and add some pinkish lights in the windows, as well as turn the building form white to light grey to be less pure and clean. Similarly swap the symbol of the guildhall and and swap the flower bed for pink red and purple flowers, again tweaking the lighting and colors of the buildings, try to make the two side doors windows with girls in them, stripper poles or somthing. For the farm maybe start with horses in a stable and swap to girls or other such livestock swapped for livestock play. For the training field swap the targets equipment for wooden horses and other sm equipment, the tents becoming cages. 

Of the other icons one seems church based, start with a outdoor podium and seating, like in a church but outside (similar to a outside wedding) swapping the podium eventually to a pillory.

If I knew what the other two icons will be called it would make it easier to give ideas.