Point 1 is an issue today with the small reverse-osmosis plants that several coastal cities have already built. The argument, however, runs: "R-O is expensive and we don't get much water for the size of the plant, so why put up with the ugliness?" But what if the minds of SV could come up with a technology that was ten or a hundred times more efficient than R-O, and a realistic source for city-sized volumes of water? Think of there being a square-cube law for ugliness.
Point 2 is typical swill from "environmentalists" who know nothing about science and have no real appreciation for large-scale systems. Desalination plants to not create salt; they just temporarily separate it from the water. After the water is used by humans, it makes its way back to the sea and is reunited with the salt. In fact, desalination gives us the option of leaving the salt inland, REDUCING the amount of salt in the ocean. Salt has innumerable industrial uses, and has been a prized item in commerce for millennia. Furthermore, being able to build really large desal plants would make it easier to extract all sorts of usable minerals from the concentrated brine at the output. Move enough water, and it becomes practical to do such things as extract uranium from the sea to power the plant.
Point 3: Here in Arizona, we would be glad to add more reactors to our nuclear complex in Phoenix to send more power to California. We're already making a fortune from Californians who refuse to generate their own energy.
Point 4: Yes, NIMBYism and Luddism killed the California bullet train, which all the liberals wanted until the moment construction actually started. But water is an even more vital need than transportation. Watch for thirsty farmers to start shooting lawyers while the whole nation applauds.