Thranduil makes it clear that he doesn't consider Tauriel to be worthy of his son, Legolas, but the film avoids explaining why. In the books, it is established that the wood-elves of Mirkwood are Silvan, but Thranduil and his family are Sindar ('Grey Elves'), a more noble ruling class of elves. This difference is also alluded to in the film by the fact that Thranduil and Legolas are blonde, while all the other Mirkwood elves have darker hair ( although Legolas' hair colour was never declared in the books).
Robert Kazinsky was cast as Fili and had filmed a few scenes, but left the project and returned to England about a month after filming started due to personal reasons. He was replaced by Dean O'Gorman.
Balin: [sees a chamber full of dead dwarves, with their only means of escape blocked]
The last of our kin. They must have come here hoping beyond hope. We could make for the mines. Might last a few days.
While discussing with Thorin about dragons, Thranduil's face briefly changes to reveal ghastly scars. The scene is not from the book: the movie seems to imply Thranduil is using some sort of enchantment to conceal the wounds he has received in the past while fighting dragons (not Smaug).
Are there any additional scenes after the credits?
I thought the "last light of Durin's Day" was supposed to be the sunset. Why is the moonlight in the film?
It is in the book, but the movie scriptwriter decided to add the "plot twist" of making it the light of the moon. The main reason Tolkien did not write this in the book is because it is an error. The Moon has no light of its own but shines only by reflected sunlight, which is why it shows phases (the lit half always faces the Sun). Hence a full moon at sunset can only be a rising moon, and the Moon would be in the eastern sky (on the other side of the mountain) and could not illuminate the keyhole. In addition, a full Moon would be up all night, so its light at sunset would not be the "last." Tolkien, who took great care with moon phases, would never have made this mistake.The scene is written this way for dramatic effect: by having the dwarves leave in disappointment and frustration. By having Bilbo discover the secret, it heightens the drama for the audience.