She is 6,000 years removed from the Lord of the Rings though, and this is before she acquired her great ring, and the responsibilities that went with it. I think it makes sense that we see her in a younger, more raw form.
Yea, if you look at elves in the books, they made a bunch of crazy mistakes all the time. In LOTR they are all calm, wise and peaceful, but that's after several millenia of massive screwups.
The dialogue could have used a couple more passes to be more subtle and cleverly written.
It is important to remember that Tolkien was like a British gentleman: well-mannered with a sharp wit. All of his characters have that same coloring to them.