You need more contemporary arguments. Whilst it is imperative to mention Australia's historic CAD, there have recently been record trade and current account surpluses which remove the need of foreign borrowing to service debt. Whilst we have a small export base, it is still quite competitive due to China's historic and CURRENT demand for our natural resources. Sure, the Savings-Investment Gap has created our historic CAD, but our NPI deficit is now millions lower due to record-low interest rates around the world. Sure, exchange rates has historically increased debt but NOW most of our debt is denominated in Australian dollars or hedged through financial instruments, and thus a depreciation of the Australian dollar would lead to a decrease in the NPI deficit because the increase in the value of foreign assets in Australian dollar terms would outstrip the lowering of minimal debt denominated in foreign currency. As a result, it'll be hard to get into an A range with your current essay.
Nah. I'm just a year 12 student, although we had a similar question on external stability in Term 2. I reckon around a 15 since you cover your paragraphs in good detail and stats. There are 2 structural factors (narrow export base and savings-investment gap) and 1 cyclical factor (exchange rates). You could talk about more cyclical factors that affect external stability such as terms of trade/domestic economic growth/global and domestic interest rates + add in the contemporary stuff rather than all mining boom.