Years ago, Sheldon Brown recommended your #2. If your front tire wears so slowly that it lasts for years, then moving it to the back is a good way to wear it out before it starts to die from dry rot.

If you ride enough miles that your front tire last less than a year on its own, then I would go for #3.

#1 just sounds dumb.

Some people use different tires on the front and rear (e.g. a more puncture resistant tire on the rear), so their choices are more limited.