You say "over" when you are finished with a statement so the other person knows when you are finished. Example: Tim: "I need you to do this. Over." Lisa: "Roger. I will be able to do that in a few minutes. Over."
Ten other people. In addition to the benefit of extra sets of hands, there is a lot to be said for the mental health benefits of having other people around.
Yes, as long as you are text bombing someone, it will keep sending text messages. In some text bombers, you have the option to limit the text messages sent.