I like Japan --I think for a mid-sized country they have done well for themselves... but their representation in foreign reserves is a bit outsized. The Yuan, given China's economic strength, has nowhere to go but up. We'll have to see how European Central banks like that in 10-20 years when they exert more influence on policy.
The yuan is not convertible, like the yen, dollar, and euro are. It doesn’t float, it’s exchange rate is set by fiat. When the yuan is actually traded in the wild, then it will move a few steps closer. I don’t think the government will ever let it get stronger than 6 rmb/usd, it would absolutely ruin their exports.
Trade might be controlled, but definitely not flat http://www.xe.com/currencycharts/?from=USD&to=CNY&view=10Y