When it comes to National Interest, Global Politics is more interested in "why" than "how". The questions you should be asking yourself (and what your knowledge should relate to) is why the national interest is what it is, what they've done to secure this national interest element and how successful they've been.
The lion's share of marks does come from describing specific things your state has done (your random facts, preceded with a "For example _____" or an "as seen through _____"), but it's strung together with a sustained discussion of why your state does the things it does, and how well it has achieved them. I can't see where you would ever need to mention the Cold War, same way you very rarely need to discuss a state's "historical power", as it requires you to refer to exclusively pre-2000 events.
So, China wants to develop its economy because it directly strengthens its military, cultural, diplomatic and (obviously) ecoanomic power, and this power helps it achieve other dimensions of its national interest. Ways China has chosen to pursue economic development include joining the WTO in 2002 and/or allowing private home ownership and/or the economic instrumentation of the SARs, which has had the effect of (building international trade up to 2.1 trillion dollars in 2007/7-10% economic growth for the past 20 years).
Super specific detail on the mechanics of economics, like currency manipulation, is not expected of you at the year 12 level, but, used correctly, references to it may score you brownie points.