I'm planning to go from Kuala Lumpur to China. Is it easy for an Australian to get a Chinese visa in Kuala Lumpur ? What documents do I need ? How long does it take ? And how long can I get a visa for?
No (Unless you are a resident of Malaysia and can proof so). You should apply in Australia or your country of residence.
The Malaysia site of VisaForChina has a step-by-step guide and when you complete that you will find a list of requirements:
(3) Proof of legal status (applicable for those not applying for the visa in their country of citizenship)
If you are not applying for a visa in the country of your citizenship, you must provide the original and photocopy of your valid certificates of residence, employment or student status, or other valid certificates of legal stay provided by the relevant authorities of the country where the Visa Centre is located.
If you are just travelling through Malaysia that will likely not convince the visa officers. China does apply this policy world-wide that you should apply from your country of citizenship or residence (an exception existed at least in the past through HK) so a change of itinerary won't alter your result.