Disturbing scene about a puppy being killed and something sad / cruel with the mother afterwards. Will not give details for triggering reasons. Do not read if these kinds of things trigger you.
Considering the circumstances, kind of? There's no actual sexual content including a minor, but the way some minors are presented from the protagonist's POV, it does seem like he (not the book) thinks of them as objects to satisfy his wants.
The protagonist. He's raised in horrible conditions without a single show of love and care from any adult around him, and he ends up becoming a horrible human being.