- building/operating the electric grid, esp. UHV lines, and relevant R&D
- oil and gas pipelines
- building/operating rail lines, esp. HSR, and relevant R&D
- building/operating telecommunications networks, and relevant R&D
- building/operating the national water network
-Commercial utilities for the above
I largely agree with this list.
key equipment
The best electronic equipment makers in China are not SOEs.
grid scale energy storage projects, esp. pumped hydro
Don't see why private operators cannot do this as well as SOEs.
- coal mining
- metals mining
- metals refinement
World's biggest mining companies are not SOEs. Whatever refrains about the safety track record of POEs in China can largely be traced to the problematic regulatory/enforcement mechanism of local governments, not necessarily a conclusion that "mining is better left in the hand of the state", but rather the state had poor regulatory enforcement capacity.
-commodity chemicals
Again, nothing to suggest the state should do better here.
-rare earths
Strategically, yes.
- airlines
This is yet again a sector where it's not clear. SOEs and POEs can do very well (Xiamen is an SOE, Hainan POE).
- bulk shipping
Again, not clear why SOEs should do better here
- building a complete indigenous defense-industrial base nearly from scratch
This for sure.
- civilian shipbuilding
Eh, yes and no. I would frame this as the State need to maintain capacity but not necessarily look to dominate the sector.
- civilian passenger jets
Considering the conjoined nature of civil/mil in aviation this is really not separate from defence-industrial sector.
-a whole lot of obscure but very important industrial/agricultural machinery that would otherwise not be developed domestically or only developed to the point where they could be monopolized and then no further
Not sure why you'd write off Sany or Zoomlion as uncredible at ag machinery. You can support these sectors with basic research funding and allow the researchers to spin off of the labs/universities to form their own businesses.
Overall, it is extremely important to not conflate the necessity for "state support" with the necessity of "state ownership".