Short answers, pulled from the story.
Austen Chamberlain won the Nobel Peace Prize for his role in negotiating the Locarno Pact of 1925. He, French representative Aristide Briand, and German Foreign Minister Gustav Stresemann signed an agreement in the Swiss town of Locarno committing France, Germany, Belgium, and Italy to settle all future differences by arbitration rather than war.
No, Austen Chamberlain never became prime minister. He twice came close, in 1911 and again in 1922-23, but stepped aside on both occasions to avoid splitting the Conservative Party. Until William Hague led the party from 1997 to 2001, Chamberlain was the only Conservative overall leader in the twentieth century not to become prime minister.
Austen Chamberlain was the older half-brother of Prime Minister Neville Chamberlain. Both were sons of Joseph Chamberlain, but by different mothers. Austen died on the 16th of March 1937, just ten weeks before Neville became prime minister, the first member of the Chamberlain family to reach that office.
Chamberlain resigned in July 1917 after an inquiry into the disastrous Mesopotamian campaign of 1915, which included the loss of the British garrison during the Siege of Kut. As the minister ultimately responsible for the separately-administered Indian Army that conducted the campaign, he accepted responsibility and stepped down. He was widely praised at the time for the decision.
Chamberlain spent twelve months in Berlin as a young man in the 1880s and attended lectures by the nationalist historian Heinrich von Treitschke. He left with a lasting suspicion of German nationalism, describing what Treitschke had revealed as "a narrow-minded, proud, intolerant Prussian chauvinism". He later reflected on those impressions during both the First World War and the crises of the 1930s.
Austen Chamberlain's personal and political papers are held at the Cadbury Research Library at the University of Birmingham. A separate collection of letters relating to him is also housed there.