I am not sure if its enabled for regular members but you should be able to go to your user cp and view them there (shows what thread and post and comments if the person left any) ..
i don't think that's possible. he can give you some positive/negative points but he can't give you more again, untill some time passes or he gives points to someone else. he'll get the message, soething like: "you have to spread more repuattion around before you can give it to jeeks again"
btw. jeeks here's some for that "illegal" act you helped me out with.