Answer:

1. Einstein is not necessarily the smartest human to have lived; that title goes to William James Sidis, having an IQ estimated to have been between 250 and 300, higher than Einstein's estimated IQ of 160 to approximately ~200. However, that does not negate the fact that he helped to discover and contribute many things in the field of science and its branches. The theory of relativity, e = mc², and the development of quantum theory, just to name a few.

2. For simplicities' sake, the inventor of the telephone is often credited to be Alexander Graham Bell, as he was the first to successfully patent the idea.

3. The concept of "school", and subsequently "education", has been around for millennia. From the ancient Romans, to the classical Greeks, to the enlightened Italians, and so on and so forth. There is no way to dictate or pinpoint the invention of the general system of schooling onto a single person, state or organization.

4. Roberto Nevilis is credited as the inventor of the "homework". Going back in time, we see that homework was invented by Roberto Nevilis, an Italian pedagog. The idea behind homework was simple. As a teacher, Nevilis felt that his teachings lost essence when they left the class.