Here are a few questions regarding the causes of the Opium Wars that I'd like to have some comments on by people more qualified than I:
1) Could the early discovery of silver deposits in Australia or (OTL) British Columbia (the Oregon country) allay the fears that trade with China was depleting Britain's bullion reserves?
2) In the same vein, do you think the Chinese would be willing to pay for Australian opals?
3) In a TL where South America was more stable and better integrated in international trade networks during that timeframe, could coca replace opium as the main import drugs? And what about khat?