Internal consumption is risky when it comes to China; China's had growth levels of roughly 5% of GDP in terms of household debt to GDP as of late; the implication is that within 7-8 years, China will reach South Korea-like levels of consumer debt, which is clearly unsustainable.
Moreover, exports are superior to internal consumption as a way to grow the economy. Consider the failure of import substitution in many Latin American countries, or the fact that most successfully developed countries were export dependent during their period of high growth. China's exports as a percentage of GDP roughly amounts to 17% of GDP, not the sub 14% you've stated.
You should also consider that the United States and the EU make up, individually, roughly 20% of Chinese exports or 40% total. Roughly 40-50% of Chinese exports are to non-aligned countries, so the US stuffing sanctions on China, as it seems to be aiming to do, can be strongly destabilizing in terms of exports.
====
On an economics front, roughly, China has issues with high corporate debt levels, an aging population, and a current failure to control the commanding technological heights. This is important, since for China, basic capital accumulation is there, and further growth has to be accounted for by TFP growth, which is both organizational and technological.