I see nothing wrong with non-CA renewable energy feeding in. In a way, it's consistent with everything else about California especially, and the US in general: export your impacts as much as possible, while making use of the products. Nevada does have some good-sized solar ranches, which would probably be happy to sell to CA when the spot prices are higher than they are in Vegas.

That doesn't reduce the need for locally-produced energy any. The nearer it's produced to where it's consumed, the lower the transmission losses. Managing system stability with a lot of local pop-up generation can get interesting, though. If Jerry really wants to get to 50% renewables before 2050, for instance, I think there needs to be a lot more attention paid to storage both grid-based and at production sites (those panels on your roof) to better match the production-consumption curves. At present, fossil-fueled (even if just n.g. powered) have to be kept in spinning reserve to come on line quickly when the wind drops and the sun goes down.

As far as 'carbon-free HSR' is concerned - that gives me a mental picture of a Pokemon cartoon of bullet trains and mad scientist castles with windmills lazily turning everywhere.