Quite. I said when I reviewed the movie it was a slight plot and an excuse for a few action sequences. The movie at least made the most of those sequences. In the book they're a small part and padded out so much that the entertainment value doesn't really outweigh the flaws you raise. In the movie you're distracted enough by shiny dragons so as not to notice so much.

That particular issue stands out all the more because they spend so bloody long explaining everything at the end of the book and it gets so convoluted that it never seems a natural conclusion.