Global and macro economic theory is very complicated. Economists build models to try to understand, and help governments predict for example how a proposed socio-economic program will impact a society. The good ones get Nobel Peace Prizes when they are accurate, but their models are always being re-tooled, scrapped and re-built. That's because societies and cultures change. Spending and saving habits change. Countries move from agrarian (the U.S. in the early/mid 20th Century and China, I don't know, NOW) to an industrial economy. Trying to justapoze a few factoids onto a nation or culture or predict its future with any accuracy when the entire mosaic isn't understood simply doesn't work.
And economic theory suggests that governments should spend LESS when the economy is booming and MORE when it is in recession. Its called Keynsian theory and was initially explained by John Maynard Keynes during the Great Depression as the solution to getting out of it. Roossevelt employed it to move out of that rut, as did Bush and Obama during the Great Recession. The theory runs counter-intuitive to humans but makes sense when you actually think about it. Let the private sector fuel growth and governments cut spending during great times and governments prime the pump by spending and getting people buying and selling during bad times. That's how most governments work now, but it took decades to get it. My point is trying to look at a snap shot of China right now and make solid predictions about it, when it is similar in many ways to the U.S. 75 years ago is fruitless.
So the Chinese may be getting it completely right, but there are very good historically accurate economic reasons to suggest there may be a few bumps in the road. A GDP of 3 percent annual means that the economy will double in 24 years. A GDP of 7.5 percent would mean a nation would double its economy in less than a decade. That is so fast that it doesn't typically allow nations to re-consider investments, tack in the wind, adapt to changing social, environmental and political changes. Big mistakes are often made. That's why a 3 percent growth rate is desirable, as it allows for all of that and is better for planning long-term.
As I pointed out in your previous post about this, economic theory is very complicated and takes years or decades to become clear. Google Economist jokes and you will see. The government official, and the person who wrote that article you posted, are clearly not experts. Find better material to quote/reference.
As far as military spending, geesh man, google the percent of U.S. military spending as a part of the GDP since the Eisenhower Era (you referenced this in a previous OP about the same topic) and you will see that it has actually gone steadily down since that time, with blips in the 60s, 80s (Reagan's increased military spending which many credit in large part to the end of the Soviet empire and Cold War-so much for a hawkish/militarist mindset) and 00s (post 9/11). Obama is cutting military spending deeply, and has proposed addiitonal cuts. On a side note, don't think for a second that the U.S. current mindset of rolling back its military spending isn't one of the things Vlad considererd when he went into the Ukraine. There is so much more to this topic to consider.
Things are complicated. You make some very good posts, but your anti-west bias colors your views on these topics. Ive got an MBA and have studied and taught, at the college level, global, macro and micro economics theory and application. If you want to trade facts - not factoids- about this topic, lets lock and load. And don't get me started about U.S. military might and its technological capabilities. I won't be able to share what I know. But I know.