Electricity, sure. Land, no. The reclaimed land will be highly salinated and unusable on top of the climate being very hot and very dry meaning the salinity level will be unlikely to change in the near future.
Not too sure about the difference. The water level would just drop, and the water simply flow away from the shallow coastal areas. I don't know what would salinity the water would have reached after dropping 200 meters but it's not the one you get if you simply let a volume of water to evaporate completely, which would be 100%.
It's how the Great Salt Lake and the Dead Sea got super salty? The salt doesn't evaporate away with the water, leaving a higher concentration of salt in the remaining water. If it all evaporates away, you wind up with a salt flat.