Faces of Fire contradicts "Star-Crossed" because they show Kirk learning of David's existence in two different ways, years apart. Also, I think David's ages in the two are incompatible.
Most of these books and comics were written at a time when continuity among tie-ins wasn't permitted. As a rule, one shouldn't expect any consistency among them. Nor is there any reason why that should be an overriding factor in whether they're worth reading. They're all make-believe stories anyway, so as long as you find them enjoyable to read, so what if they imagine things differently? It can even be fun to explore the different alternatives that different authors have come up with for how various events happened.
As I see it, continuity is a secondary concern. Just read books to see whether you like them. Then, after that, you can look into whether they fit together or not. Heck, you can make that determination better after reading them yourself than you can by asking for other people's opinions.
Exactly - then for me, I like to compromise on any inconsistencies, draw my own conclusions, for myself only, so I can live within my own little c-word existence.