I'll answer for art, he will probably be back later.
Yes, some diesel and gasoline is included, I think mostly to Latin America.
Several factors- Agreements with other producers and consumers, location of refineries, type of crude.
Not all U. S. import is crude- more refined product is being done "on site"- Total, Shell and Ex-Mobil as well as Saudi Aramco have cooperative refineries with the Saudis, and some other producers are doing the same. Processed natural gas has increased this trend.

(Digression- just saw where Sinopec, one of the Chinese companies, has bought part of one of the U.S. fracking companies for $2 billion. Haven't heard of opposition being raised.)