So I live in the U.S and I have family in Korea. Obviously there is a great opportunity for arbitrage but was wondering if there were any downsides to it. I would buy bch/btc/eth here then send it to my cousin in Korea and she sells right away for 50-60 percent more. Is there anything wrong with this plan??
It is the fantastic opportunity both for you and your cousin in Korea. This opportunity mustn't be thrown away even if the Government won't be so fond of it if they find out the origins where the transactions came from.
I doubt that they will track the suspicious movements of your transfers but if the cousin exaggerates with the transfers to the cash they might get suspicious.
Bitcoin as a decentralized currency is strongly opposing every government and I highly support you to drain the government, in this case, Korea, of their central funds.