Avoiding the Opium Wars

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?
 
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?

1) No not really. Wasting silver on tea was seen as a bad exchange and opium was cheaper and easier to obtain.
2) No not really. Volume of opal trade was insignificant compared to tea
3) Coca - possibly. Khat - no. Opium was a status symbol in some Chinese circles as it was exotic (introduced by Arab traders) and expensive. Coca / cocaine might be a replacement but would be more expensive (transport) and would need to build markets. Khat has none of the cache that opium had (and China would have known about Khat for some time)
 
Ah, and regarding #3, there's also the problem that once imported opium was safely ashore it could be passed off as domestically produced (as there was quite a lot of this, mostly from Yunnan, around) instead whereas Coca/Cocaine would -- if found by the authorities -- be a clearer violation of the ban on foreign imports.
 
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