Long Island (New York) is a true island, although it is connected to the mainland by man-made bridges (9) and tunnels (13, including rail and transit).
4-6 hours give or take and if you go by ferry usually 4 driving it took me 5 hrs once
Fire Island is part of Long Island. It woudl be more helpful to ask how long it takes to get to Fire Island from a particular Long Island town.
yes, long island city is in queens, which is on long island
Partially, There is always a water boundary line between states