for question one, it is because we had a revolution of information not energy, we can hold thousands of sound and image on a chip the size of a finger nail but cannot power it for more than a couple of hours while not connected to the mains. we still rely on fosul fuel and chemical batters for there to be any way of having a portable power supply for your jet pack. but if we keep working on necluar power maby some day
question 2, you need to ask a biologist
question 3, could work but it would be hard to hide it from private company or observver.
question 4, it would require us to kill all bears of a large size to decress there size over a long period of time, or use a shrink ray but for that we would need that power supply from question one.
there are my answers