Depends on your definition of wealth. Defined as "amount of time you could survive with no income", most Americans (including many in the HN crowd) aren't very wealthy at all.
Only if they insist on keeping their current (very high compared to most people in history) standard of living. A median American could survive at the standard of living of a medieval peasant indefinitely on their current assets.
Yes, but it would require one to possess a marked fondness for worms.