Well i think they still have a lot of time, and at least working on the camera work and editing wouldn't require that much, after all, it is being rendered in real time, so it's not like they have to go back and do it all again.
I definitely think they should work on that, i just think that there could be a much bigger sense of movement and action, and they have the stuff, it just isn't being presented in the best way.
And i do like action packed openings too Himuro, i don't think they are always the best way to open a game, but in this case it is, however, i believe they should give you less filler, and let it play out as this memorable opening, it's a 40 hour game, players will get used to the combat later on, no need to worry about the 1st 40 min.