The EU is a larger economy than the US, or at least has the same size.
The US might be the largest export market for China, but they only account for 20% for Chinese total exports.
China knows that while the US do not seem to always realise that China is their largest customer in a number of industries (ask soybean farmers or chipmakers).
As for the currency, well if you work in Forex you know that the yuan is actually over-valued (not under-valued!) so China does not have to devalue, they just need to do what the US ask them to i.e. let the market decide (that's what they've just done to send a message to the US).
> No one wants to deal with a partner who bullies them around.
Isn't that exactly what China should be thinking right now?
This is not as one-sided as you suggest.
A good recent piece on this by Paul Krugman in the NYT: https://www.nytimes.com/2019/08/08/opinion/trump-china-trade...