i would give this link a look it has alot of good info on housing flat rock scorps. Other than the housing, Temp 85F, low humdity misting maybe once every couple of weeks depending on evaportion. i would also keep a water dish at all times in the tank. 3-4 crickets a week depending on size. All in all i think that the housing set-up is most important in keeping your flat rock happy
You need to keep flatrocks warm, I would use a red heat bulb at one end of the encloser. Also you need to use lots of rocks laid out in a well planed setup. They need to be able to hide to be happy. Given that they should thrive.