Sure. 600 C is about the temperature of steam in a coal fired power plant, so one of the use cases here is to take an old coal plant and replace the heat source. It's much higher temperature than the steam in a LWR, so the turbine can be smaller and cheaper. Also, no steam generator is needed as in a PWR.
Yes? That doesn't mean the capex of a steam turbine for this application would be unaffordable, or that this wouldn't have superior economics to nuclear (which also has a steam turbine, and a more expensive one).
Re: Nat gas, agreed, it’s not solar though, storage is much more expensive
Thermal energy still needs to drive a turbine to generate electricity