As far as sloping, I'm pretty sure Main Street is relatively flat, except for the obvious slope to each curb for drainage. Also, the street does not narrow from one end to the other.
They also put the buildings close to the train station, but then put a large space between the end of the buildings to the castle, at the other end of the street. This way, the castle looks a LONG way away, when you come in and first see it. But when you're tired at the end of the day, and walking out, the train station looks closer because it's actually 1:1 scale and right at the end of the side buildings.
Another note on the main street buildin facades: as others said, each story is a fraction of the height of the story below it. For example, the first story is 1:1, then the 2nd is 7/8 the height of the first, and then the 3rd (if there is one) is 7/8 or some fraction of the 2nd story. When you look in the upstairs windows you see curtains and a wall, or dark space. In reality, all of the Main Street buildings are 2-stories, with a basement (tunnels). the top two floor facades merely hide the 2nd floor offices and the A/C equipment on the rooves.