That Auto Triple switch is just the thing to add to your Xmas Layout as it gives a variety to the trains rater than just run around and around. Great luck for you finding something you have longed for too.
As far as people size for the layout...I am not sure about Hot Wheel people...or just don't remember what they look like. If you get the chance might you snap a picture of one next to a Plarail coach? I actually thought that the HO people were just right as realistic in Plarail. When you stand one up in a doorway or Steamer Cab they seem pretty close at least.
Oh, and no need to apologize for your absence as life always gets in the way of our playing with toys as we get older and have responsibilities.