They pretty much had all they needed resource-wise in the country, trade was not a prerogative and even though Zheng He did go out exploring they were not interested in colonies or mercantilism.
Mercantilism was pretty much frowned upon within the Confucian system, merchants did not produce goods they moved them around and made money which made them a drain on the system. The few who were enterprising and maybe came up with some new product might often find themselves in competition from the government
The Emperor system considered itself the center of the world, the focus of the heavens. When outsiders came they gave tribute and fealty to the Emperor, so the outside world came to them, they did not need to go out
yes it I true that there is a great possibility of hydropower generation in Nepal, the electricity has not been supplied as required because of the following reasons:
