Regarding #7, of course back when the original trilogy was being made it was about Luke and he was the main character. George has never denied that. He even admitted in one of the ROTS featurettes that Vader was originally just going to be a pathetic henchmen, but because he became so iconic he eventually grew to be the amazing complex character we have today that is now the most well-developed in all of Star Wars. After George made the prequels it become the story of Anakin/Vader as the prequels focused on him and he was a prominent figure in the original trilogy, his character journey being concluded in those three movies (which by the way, just shows how good the original trilogy is; it satisfyingly concludes a character journey created 20 years later). You can’t say the entire saga is about Luke when he’s only present in 4/6 movies, and he’s a very very very minor part at the very end of one of those four, so really only half of the saga.

Luke may be the protagonist of the original trilogy alone, but the whole overarching (pre-Disney) saga is about the rise, fall, and redemption of Anakin.