Short answers, pulled from the story.
The Return of the King was published on the 20th of October 1955 in the United Kingdom. It was the third and final volume of J. R. R. Tolkien's The Lord of the Rings, following The Fellowship of the Ring and The Two Towers.
Tolkien felt the title revealed too much of the story. He had proposed The War of the Ring as his preferred title for the volume when he submitted his book titles to his publisher Rayner Unwin in 1953. Both of his preferred book titles were eventually used in the Millennium edition, published in 2000.
The Scouring of the Shire is the penultimate chapter of The Return of the King, in which the four hobbits lead a rebellion against occupiers directed by a figure later revealed to be Saruman. Critics have called it the most important chapter in the entire novel. Tolkien designed it to counterbalance the main quest to destroy the One Ring with a moral quest to purify the Shire and accept personal responsibility.
Reception was divided. W. H. Auden called The Lord of the Rings a masterpiece of the genre in The New York Times, while Edwin Muir attacked the completed book in The Sunday Observer in 1955 as a boy's adventure story, comparing it to the works of Rider Haggard.
Tolkien gave two reasons for placing the tale in the appendices. The tale covers events both before and after the main narrative's timeline, making it difficult to embed in the story proper. Additionally, the main novel is narrated from the hobbits' point of view, and the love story of Aragorn and Arwen lies outside that perspective.
The appendices include the Annals of the Kings and Rulers, a complete timeline called the Tale of Years, sections on calendars and language systems, and family trees for the major hobbit families. The Tale of Years records that Sam eventually gave the Red Book of Westmarch to his daughter Elanor before crossing west over the sea himself as the last of the ring-bearers.