Insulation = less $ for the trains, it's bearable. I had a house in college that had no heat. I'm used to being indoors in winter jacket, hat and gloves
You should be OK. Just allow for expansion and contraction of rails. My biggest enemy, was moisture. Well ventilated? Boxcab E50
Yes, attic fan with controlable thermostat. There is also a window on each end, tremendous help this summer.
