Firstly I would say that the idea this film is inevitably doomed is total nonsense, the books are flying out of the shops and he was the second best selling author of last year. People are talking already about who is being cast in the roles and they haven't even thought about filming it yet. This film will be eagerly anticipated and will almost certainly do good box office. What are you basing your idea on that it is doomed?
Secondly, although this guy translated the book, it doesn't give him any more insight into what the character should look like when played on screen than you or me. He had no artistic input into the character and as such his opinion is simply that, an opnion. He hardly speaks for Stig Larsson. He clearly feels he wasn't paid enough for the translations and so neeRAB to make more money by spouting this rubbish. Who is this guy and what qualifies him to make these assertions?
Thirdly, there is no way on earth that we can know how good or not she will be until we see the film. But someone has chosen her and I suspect that someone involved with the novel will have approved her.
Fourthly, as others have said, she's supposed to be tiny and skinny. Rooney looks about right to me.