By Warriors I assume you are talking about Warrior Cats? I have not read it but I was under the assumption that was a childrens book seeing as how it features cats. When someone says young adult my mind goes to books like Catcher in the Rye or Lord of Flies.
Young adult means the content is suited for a younger audience, it’s not an excuse for unintelligent writing void of anything of value.
Yes you can delete any comment from anyone on your post, and you can also set it so you need to approve any comment first so the negative ones don’t even show up at all.