I’m confused are you saying that negative voltage is more deadly than negative voltage? Just because electrons flow from negative to positive doesn’t mean it’s any more dangerous what moves the electrons is the voltage potential. If you were able to have electrons flow from a source through you to the ground your just as able to have electrons flow from the ground through you to a positive voltage source.

This isn’t necessarily true they could use the brayton cycle at the higher temps a fusion reactor operates at. So instead of making steam it would just be hot air. This is more efficient but might not be used or whatever reason.