I think you got it backward. Chinese navy doctrine in 1980 is brown water navy meaning they only adjunct to the army and their doctrine called for coastal defense So that is why they don't have long duration cruise and not because of the quality of the ship.
In that respect they fulfill their design requirement Only in the late 90 when Admiral Li Huaging come with first island and 2nd island chain did they develop doctrine for long range patrol and therefore the requirement for ship that can endure long range patrol.
So in that respect that ship meet their intended design requirement and since as you say they were involved in actual combat on the sea and come out from it in one piece I think that alone is testament to the ruggedness of that ship
No, navy was always independent organization from its inception.
strategic wise (and some times operationally) it may be playing 2nd fiddle for the army true.
the fleet building was always driven by resource expediency
the first true fleet building program (-051 destroyer/ Replenisher/ Sub Rescure/ Ocean tugs) was laid down as a piggy back of the DF-5 ICBM program needs. although not a minority in PLAN secretly feels that thats a good opportunity to increase the range and capability of PLAN, long the junior partner in PLA organization.
PLAN strategy was driven more by lack of resources and technology then some fundamental lack of will to expand into blue water operations.
, but hard to tell since we dont see it in the same picture as 581!