

Sodium and water is… kind of spectacular:
But sodium ions and water are something we deal with on a daily basis, when we salt food. The characteristics of elemental sodium, as a metal, are basically irrelevant to discussing its safety as ions or bonded in molecules.



With mirrors, the maximum power is whatever sunlight hits the area of the mirror. Which for these satellites is 324 square meters. With solar irradiance at 1361 W/m^2 , that’s only 440 kW of energy, probably spread over a very large area, and not all of the spectrum useful for whatever you might want to use it for.
It’s an unbelievably stupid idea, but that also swings the other way in that it would be highly ineffective for any nefarious purpose, and will probably run out of money before it scales up to where each annoying satellite really does damage to visibility in the nigh sky or anything like that.