No. Not always. People's past ain't who someone always gotta be. If they meet that one special person, and stop being immature and grow up and are ready to settle down, and find that person they truly have feelings for, it may change their ways:)
Well, I'd say it depends. It might be that the person who has cheated will do it again, as now it's psychologically easier, but still, sometimes the person deserves a second chance. It's up to you to decide that if you ever have to.
Not always. It depends on the reason they're cheating. If they're doing it because there's someone 'hotter' probably. If they're doing it because they truly love the other person more, probably not. But it really depends on the person and why they're doing it.
Obviously I cannot speak for all cheaters, but whenI was in College I dated a few Women and there were more then a few times when I was unfaithful. After College it was a different story. I was faithful in every relationship I was involved in, including a 7 yr Marriage. So I would say no!