I'm curious. How did you get either of these from the article?
The only "trade policy" discussion was with regard to shippers giving extra-low rates to goods headed back across the Pacific to avoid deadheading. That's a company policy, not a national one.
There may be a good discussion to have on the topics you bring up, but not based on this article.
from this:
The other: How could it possibly make economic sense to ship a bulky product such as alfalfa hay 7,000 miles to China?
The answer, said Zhang, involves the enormous U.S.-China trade imbalance. Because China ships so many goods to West Coast ports,
without an 'enormous...trade imbalance' there wouldn't be all those empty container ships offering large discounts for China-bound freight. It's only because of the large discounts that exporting alfalfa becomes profitable. Foreign demand drives domestic price.