Counter to that, I'd say that the end of wind and truth, and to an extent both RoW and OB, are the setback of a greater whole. We need to remember that this is merely book 5 in a 10-book series. Yeah, it's the end of arc 1, but it's a much reduced impact(?) of an arc. Instead of something like Era 1 that ends quite dramatically and finally, this ends in a massive cliffhanger. Regarding this series as a ten-book one rather than two five-book series is something that I think is very important to narritavely understanding this series.
Besides this one point, I agree with your quite well stated beliefs.