Ok, I agree that these points might have been made more constructively, but ... They're mostly legitimate, good-quality feedback for a new C library. _create/

Ok, I agree that these points might have been made more constructively, but ... They're mostly legitimate, good-quality feedback for a new C library. _create/_destroy -- yes; custom allocator, logger, debug level setting -- yes; returning a file descriptor -- yes; the implied suggestion to move stuff out of the header -- yes. This is important feedback. These things will require a breaking change down the line unless you tackle them before 1.0. I encourage the author to take this onboard: it'll make your own life easier and your library a better C citizen.