"This book is boring. I don't want to read it anymore."
Yes, but 1. that would be translated "very boring", and 2. "_死了" is 口语 or colloquial and informal.
Not exactly. 看 is perfectly fine (maybe even more common) when referring to casual reading. See: https://forum.wordreference.com/threads/看-读.3083099/
我不想再读了/我不想再看了 is a better translation, since the '再' means 'anymore' in this case. Otherwise it would just be I don't want to read it, right? Or is that given by using the '了' at the end?