Of course, we don't know how much of the unfinished content was voice acted, but even if most of it already is, you must also take under consideration that it's doubtful they did it for all languages at once, most likely limiting themselves to English until very late into development, which means they still had to record all of that for the other versions.
I don't think so. Some part of the Polish VA was done before late 2013. I doubt that they gathered the actors to say only few lines in VGX trailer. At least the quest from 2013 closed door presentation was fully voice acted in Polish version.