The answer to the bonus question is opium. In particular the Forbes family (not related to the magazine folks) traded about 20% of all the opium sold in China during this period with the other 80% coming from the British East India Company and other UK-based trading houses.
Fun fact, the Forbes family is still one of the wealthiest families in America, they own their own massive private island called Naushon Island right next to Martha's Vineyard. They also have their own family museum in Boston where you can learn about their trading history in Asia which I'm super eager to visit And the patriarch of the Forbes Family today is... wait for it... John Kerry. When Obama made Kerry his secretary of state the Chinese weren't super thrilled, they have a long memory.