Short answers, pulled from the story.
The word helios comes from a Proto-Indo-European root that ancient scholars trace back to the dawn of language itself. Walter Burkert noted in his 1985 book Greek Religion that both Helios and Eos possess an impeccable Indo-European lineage in both etymology and status as gods.
Phaethon asked his father Helios for permission to drive the sun chariot for a single day despite warnings about danger. Zeus struck Phaethon with lightning killing him after the boy traveled too low burning the earth and too high freezing it.
Ancient artifacts present Helios as a beautiful full-faced youth with wavy hair wearing a crown adorned with the sun's rays. The radiant crown traditionally held twelve rays symbolizing the twelve months of the year according to descriptions found in marble reliefs and coins.
The island of Rhodes served as one of the only places where Helios was worshipped as a major deity in ancient Greece. Pindar's Olympian Odes memorialize the devotion of Rhodes to the cult and personality of Helios making him their founder and civilization's progenitor.
A colossal statue named the Colossus of Rhodes adorned the port of Rhodes until it collapsed after an earthquake hitting the island in 226 BC. Strabo recorded its height as seven times ten cubits which translates roughly to seventy feet or approximately the modern Statue of Liberty from feet to crown.
Anaxagoras asserted during his trial around 450 BC that the Sun was actually a gigantic red-hot ball of metal clashing with traditional religious views. Plato's Republic presents Helios as the symbolic offspring of the idea of the Good within philosophical dialogues.