Short answers, pulled from the story.
The main treaty guaranteed inviolability of borders between Germany and France. It also secured boundaries between Germany and Belgium as established by the Treaty of Versailles. Five nations pledged to observe the demilitarized zone of the Rhineland defined in Articles 42 and 43.
The German Reichstag approved the Locarno Treaties with a vote of 291 to 174 on the 1st of November 1925. Formal signing occurred in London on the 1st of December 1925. Delayed withdrawal of British troops from Cologne took place in January 1926.
Poland felt unhappy about the Collective Note added to the treaties because it stated the League would consider military capability when invoking Article 16 sanctions. No guarantee of Germany's eastern borders mirrored statements fixing its western frontiers. Józef Piłsudski declared every honest Pole spits when hearing the word Locarno.
Adolf Hitler sent Nazi troops across the Rhine on the 7th of March 1936. This action repudiated the Locarno Treaties entirely. There was no reaction from signatories other than verbal condemnation.
Austen Chamberlain won the Nobel Peace Prize in 1925. Aristide Briand and Gustav Stresemann shared the prize in 1926. These awards recognized efforts related to the agreements signed between Germany and its neighbours.