Salt is used in thermal energy storage systems because of it’s enormous capacity to hold heat. I don’t know how ceramic compares, but the latent heat involved in the state change (from solid to liquid) is important because it extends the heat that can be trapped. As I understand it, it’s not pure salt, but may also have thermal oil and high-pressure water & pumps. Depends on the usage.

I don’t think they’ve thought about crashes because none of these systems are currently mobile. Even though I would imagine that molten salt flows quite slowly, the amount of energy in it would melt/damage most things. But when it finally cools, though, it’s just salt, so cleanup is easy.

Some systems use a Rankine Cycle steam turbine, like you said. Others have been designed to use thermocouples, devices that convert nearly 100% of heat differences (over a threshold) to electricity and vice versa. It’s a form of heat pump, like those used in houses, but this thermocouple is designed for much higher heat differences. Since it’s trivially reversible, the same device is used for both directions.

One other cool hybrid is heating the salt using mirrors in a vast field, then generating the electricity from the steam engine. This means you can store the energy until later if you have more mirrors than your current grid needs.