Quote 1
So Bilbo told them all he could remember, and he confessed that he had a nasty feeling that the dragon guessed too much from his riddles added to the camps and the ponies. [...]
"Well, well! It cannot be helped and it is difficult not to slip in talking to a dragon, or so I have always heard," said Balin anxious to comfort him. "I think you did very well, if you ask me – you found out one very useful thing at any rate, and got home alive, and that is more than most can say who have had words with the likes of Smaug." (12.86-7)
In getting cocky and taunting Smaug, Bilbo told the dragon more than he meant to about where he comes from (e.g., "Barrel-Rider" = from Lake-town). But now that Bilbo has actually made a mistake, Balin is "anxious to comfort him." So Balin, at least, seems to be pulling real friend duty with Bilbo. His loyalty to Bilbo doesn't seem to be dutiful.
Quote 2
"Here," said Balin, "in the old days we used always to keep watchmen, and that door behind leads into a rock-hewn chamber that was made here as a guardroom. There were several places like it round the Mountain. But there seemed small need for watching in the days of our prosperity, and the guards were made over comfortable, perhaps – otherwise we might have had longer warning of the coming of the dragon, and things might have been different." (13.66)
Balin is one of the only characters besides Thorin who shares direct memories of the Lonely Mountain before Smaug came. Balin is also one of the few dwarves who seems to have a separate personality from the other dwarves (can you tell the difference between Bifur, Bofur, Oin, or Gloin? We certainly can't!) How does Balin's sharing of his memories give him a sense of character and individuality that the other dwarves might not have? What kind of a person is Balin?