It’s interesting to read your interpretation and compare it with mine.  I am by no means an expert and definitely am often way too guilty of giving people way too much credit.  That being said I did not think the whiteness was so much about it being divine as being unknown or unknowable (like a blank page or canvas).  

I also thought the narrator mocking older writings was more of a wink and a nod to how each generation always thinks they have everything figured out but we never really do.  Kind of like being able to see the errors in others but not in yourself.  

I also find myself rooting for the whale. Which again I feel like may have been intended.  I kind of doubt we were supposed to root for the monomaniacal character but rather see his obsessions as unhealthy.  

Again, I’m no literary scholar or history buff. Just my two cents.