1. Copper atoms are molecular grenades! They produce what are called free radicals and reactive oxygen species that can destroy any other biological molecule.
2. there are some masks made out of copper but their effectiveness is not proven. AND copper can cause toxicity
3. by simply washing away the virions
4. maybe. Yes, the infection rate is probably much higher than we thought but we have not reached herd immunity yet.
5. Just leave them alone; bats are pretty harmless but people don't like them. I, however, think bats are spectacular!