It's not technically room text, it's part of the ambient population system. The ambient messages you see in a room depend on the population density of the room, which changes based on the time of day and weather, as well as the type of turf it is and what sector that turf is on-- so the Gulag has it's own messages, as do Sinner turf and Snake turf and Art turf and Little Kyoto-- each for the different amounts of population, light, medium, heavy, packed. Some turf, like the default street, has messages for red, and gold and green and blue, with all the different densities...
But to answer your question about making interfaces, that probably what I spend 60-70% of my time doing. I just try to make things easier to pick up, easier to update, easier to understand, and require a minimum of knowledge to get right, while also being hard to break badly.