You can use this as a guide National Park Tutorial (Markers) updated and adapt it to work with a ListPicker using runtime Markers.
However based on your question you probably can use a single design time marker (Marker1); feed it the coordinates that is the basis for the ListPicker elements and then use the a ListPicker to display the location on a Map.
Perhaps. If you use virtual screens, you do not. If you use a real Screen then you need a TinyDB on each screen.