1. Seems to be more than four years out of date [1](page 9) :
> China has been transformed from being a significant importer of all nutrients in the mid-1990s to a major exporter today.
> A program to develop China’s domestic resources was implemented, and China rapidly invested in nitrogen, phosphate and more recently potash capacity.
(Nitrogen)
> China has relatively limited natural gas resources, so gas based plants account only for a quarter of total urea capacity. Instead, it has turned to its relatively abundant resources of coal, which make up three quarters of urea capacity.
etc.
( Also, China has been overusing fertilizer and has recently cut back and still increased yeild [2] )
2. Yes. China has a strong GDP growth (for what that's worth as a metric) on the back of importing, processing, and exporting to the benefit of China - as a country it is still able to survive well enough on its own (perhaps to the chagrin of the the growing Chinese middle class who demand more and more 'luxury' items).
3. China is quite capable of producing high quality steel - they have some of the highest grade iron ore imports available about the globe and they do produce plenty of high grade steel. Where we agree is that China makes an awful lot of money selling an awful lot of low grade steel.
IIRC China imports 16x the tonnage of US iron ore annual production capacity from Western Australia alone - the Chinese high grade steel production can easily dwarf the capacity of US high grade steel production capacity .. and still lose that total tonnage in the magnitude higher production of low grade steel.
It's a chicken and egg story - are we blaming the Chinese for selling low quality goods, or the world for being satisfied to hand over substantial amounts of money for low grade goods? (If they'll pay for crap, why export better?)
[1] https://gpca.org.ae/wp-content/uploads/2018/07/China-Fertili...
[2] https://www.weforum.org/agenda/2018/03/this-is-how-china-cut...