Hi,
You have indeed a Pushpin object that has a Location property. But this Location object does not have a StreetAddress object, it will be null. So even for your existing pushpins that are on a road you have to find streetinformation separate.
To know what kind of a type an object is you can do 2 things that comes into mind. This is C#, I dont know your langiage but it will be similar syntax:
Code:
if (newSelection is Shape)
// It is a Shape
Shape s = newSelection as Shape;
if (s != null)
// It is a Shape