In an invoice with a Chinese address, the country shows up before the state

This is the standard format for a Chinese address and the address for China is hard coded to have a different format than all other countries.

The address format in the invoices is tied to the country code. The country code is in the Client profile. If you create / rename a country code, then you can change over all the clients, at which point you should be able to remove the old China country code.

The address format is based on the country selected. The only alternative is to use another country code that doesn't have a format associated with it (e.g. one that doesn't exist any more like Netherland Antilles) and re-name it, then disable China.