One of the criticisms in the movie is “without externalities, no manufacturing industry is sustainable”. Do you agree? What could be done in this phenomenon?

I think that at this time, sustainability is something very dificult to reach, but it is posible. The problem is that making a change would be very expensive, and maybe not that productive at the begining and corporations are not willing to make that effort because their religion is to "maximize profits and reduce cost". An example of this is working for new technologies to make transportation not harmful for the environment, I am sure that technology already exist, but what would happen to the oil producers?, It would not be that profitable so that is why that technology have not been put in practice.
Even if sustainability was imposible, that fact does not mean that corporations can go arround the law and explote people creating a world of misery in the most of the countries and just some few holding all the money.