foot note on russia/china
for china- for charter applications you can, as mentioned many times previously ,with the right connections get a permit.The atc route offered though may not be the most optimum for your operation.
i was in BJS 2 weeks ago and met with the top floor at the MATMB and although they are doing their best to free up more internal routings the final word comes from the PLA air force on all things -airspace-
for russia - again for charter applications you have a certain flexiblity, BUT for scheduled operations on certain routes ,these are subject to your countries air service agreements with the russian federation ( i refer here to Russia itself rather than the C.I.S) and even these are further compounded if you wish to operate the 'trans siberia' routes which are still,and will remain, subject to royalties.
another advise on the above two countries,they adhere strictly to route pairings,a permit approved does not necessarily mean that you have carte blanche to change your requested OVERFLIGHT routing,(ie departure and arrival airfield )
finally,a good contact "agent" in each country although a cost item your bean counters will frown at, will in the long term get you what you want,these people after all know the system which many including myself as a westener do not fully understand.
another problem surfacing now is the issue that western banks are not permitting wire transfers to certian countries due to sanctions, 3 that come to mind,Sudan,Iran and Myanmar,this is turn means your overflight fees are not being paid and subsequently your chances of getting another due to this are also restricted.
have fun ..