What would be the economic effects of a reduction in the general level of protectionism on the Australian economy? Protectionism methods including: tariffs, subsidies, quotas, local contents rules and export incentives 

Would would be the effects of a reduction of these methods, not complete free trade.
Normally protectionism is never the answer as it doesn´t help in anyway.
If for example the subsidies for exportation were to be reduced you would see a drop in the price of items that are exported from autralia , i would place your question more in micro-economics then in macro. Not sure if that answered your question.