How long did Bruce Wayne train with the League of Shadows?

Nobody knows how long Batman has even trained in total, from comic book to comic book it varies from 10 years to 20 years. read more

Bruce already had a good foundation going into the training and it would have come fast for him. Not sure how to address your other question. Maybe Ra's knew Bruce wouldn't be cool with the idea of being an assassin at first and hoped to convince him by the time of his final test. read more

Bruce Wayne joined the League of Shadows to seek the means to fight injustice. He was still traumatized by the murder of his parents during the Gotham depression but had learned to give up on the idea of revenge. read more