Honestly, people don't realize that some words just add the effect in a story, and also the slurs in those novels are 1) because that was common in that time (Huckleberry Finn), and 2) because it helps build the effect of a dystopian future (To kill a Mockingbird). If I were an adult deciding what's okay for children, I'd follow these principles:
1. no sexual things in it, such as stuff with making out in it
2. no good morals or positive lesson, such as Teen Titans Go, which just teaches kids to brats, honestly
3. Must have some sort of educational stuff in it. Educational stuff isn't just stuff you'd learn in school, it can be survival skills, social skills, story-building skills, etc.
Anyway, sorry for the long post.
P.S. (this is in response to the illogical SJWs) why would someone ask for consent if the person can't even answer you, and the only way for them to answer you to wake them up, which was a kiss. I don't think those kind of people realize that Snow White and Sleeping Beauty were under a supernatural spell, in which they weren't asleep as in you could shake them awake, but like a coma, and the only way to wake them up was a kiss. Some people just need to use their heads. Nice post by the way :)
Sorry for the long comment