Ok, I shall answer your questions.
Why do we drive on a parkway and park in a driveway?
You can drive on a driveway as well. In fact, on some driveways, you can't park, like hotel or business driveways.
*driveway: private road connecting to public road: a private road that enables vehicles to travel from a public road to the entrance of a building such as a house or hotel.
A drive way is simply a private road. You can drive on a driveway (provided you own the driveway).
Why does a shipment go by car, and cargo go by ship?
Actually, they can go by either transportation method.
*shipment: goods shipped together: a quantity of goods that are shipped together as part of the same cargo
Essentially, a shipment is just the same thing packaged togethered and transported as frieght. A shipment of shrimp is still a shipment whether carried by car or by ship.
*cargo: goods carried as freight: goods carried as freight by sea, road, or air
Definition speaks for itself.
Why do we have hot water heaters? If it's already hot we shouldn't need to heat it right?
To keep it hot. If we don't contiuously heat the hot water, it will get cold.
What if there were no hypothetical questions?
So what your question?
is a turtle without its shell homeless or naked?
Neither. The question does not make sense.
*Naked: with no clothes on: not covered by clothing, especially having no clothing on any part of the body
since a turtle never wears clothes, it is always naked. A turtle shell is actully part of a turtle's body and without it, it would be a dead or dying turtle. It would be like me asking: Are naked or homeless if you are missing an arm? No, you may be disabled, but that does not necessarily mean you are naked or homeless.
(thank encarta dictionary tools for the definitions)