What works for one should work for the others too.

I have a savings account at Bank of China, and within that savings account, I am allowed to have savings deposited in Rmb and in a foreign currency of
my choice.  If I knew when I would leave China, I would insure that by close to that date, my savings are in foreign currency.  At departure time, I take the equivalent of 6,000 Rmb with me, and the rest either do a bank wire transfer to my account at my bank back home, or doa Western Union wire transfer to myself back home.    
What you must remember is that ALL foreigners are only allowed to exchange the equivalent of $ 500 US dollars  from Rmb to a foreign currency per day.

I don't see the problem here.... I've had Chinese friends send money back to my account in Australia, so I won't have much of my saved earnings still here!

If it comes down to it, I'll just get a dual-currency account, and keep using the funds by withdrawing through ATM's.

am i missing sth? cant rmb be converted to other currencies besides us dollars? paypal is a great way to get money out of china.

Maximum Currency exchange per person per day? Wow, you are China rookies. You don't get out much I can tell. I have exchanged THOUSANDS with ease and can at any time. There are no limits unless you never leave your posh 5 star hotel downtown and stay in the bank. Changing to US currency or any other is no issue at all. The only issue might be knowing how to spot a fake US bill. Better scan mate.

Don't keep large savings in China transfer any extra savings to your non Chinese accounts as they get to whatever level you deem to be too much. That way they don't build up.

  I work about ten minutes from my home and it can be a struggle to make it all the way with cash still in pocket, there are so many temptations. But I manage.

for me If I  stay out of  Australia for more than 90 days I dont pay tax on it

How is American or not relevant? Bank of China will send to any country.