Should be a socket closed ALWAYS if read() or send() returns <0?

Well, on Unix there's at least one other errno(3) value that doesn't mean end of the world - EINTR see for example this from send(2) manual.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.