I concur on all your points. The writing was so bad - basically middle of the line fanfic level - that at first I thought that it was a low-quality English translation; but I was assured that it was faithful to the original. When it was announced as Hugo winner, I was speechless.

I should also add that as reasonably hard sci-fi goes, the very notion of "sophons" (and their mechanics) as presented are not even wrong. In general, when it comes to most sci-fi elements of the book aside from the titular concept, it felt like someone just clipped whatever sounded cool from a popular science magazine and then tried to write a segment of the story around it - i.e. some things, like nanowires/sheets, are introduced not because they make sense in context, but solely for the cool factor.