Captain Craig wrote:
I've read that the Woodland Elves sequence is pulled from elsewhere and that Legolas is even shoehorned in(for familiarity I guess?) and that the Tauriel character is not even of Tolkien origin but I liked that character a plenty.
The elves in Mirkwood, and the party's captivity in their halls, have always been a part of the story, it's just that Jackson & Co. expanded their role, putting them into places such as the barrel sequence and Laketown where originally they were not present.
Putting Legolas into the story actually makes sense, given that his character was not created until LOTR after The Hobbit had already been written, and he was said to be the son of the Elvenking in The Hobbit. So it stands to reason that he would have been present at the Elvenking's halls during the story ( though the choice to involve him in an active role is on the filmmakers ).