2) In my opinion, the reason why Connie told the others to kill Mike was only a question of racism. Black people are not meant to be with White people. There is no respect whatsoever between those races. It was meant to happen like this. Even though Mike helped her get out of this mess, she was still reluctant and doesn’t have any sympathy towards him. The girl only wanted revenge towards anyone who was white, because she knows how some of them actually treated the Black people.
3) On the other hand, the comment gives us a hint that Mark holds grudges against people who had and will hurt him. I predict that later on in the story, he will most likely be hurt somehow, by someone. It might be someone who is very close to him, or the contrary, a complete stranger. Therefore, following these events, he’ will need to confront his own personality, either forgive the person or not and it might have an impact on him in the future.