In my 24 years of speaking English as my first language, I\'ve rarely if ever heard someone call someone else a bad egg, usually we say \"one bad apple\", but that could just be our \"dialect\" or my generation. Still, it would make sense, and it does sound a little familiar. I would say if you said that to any North American in my generation they would not take it as a strong insult, and may ignore it (depending on how much of a rotten @$$hole they are --- not sure if I can swear here, so I\'ll censor my \"french\" for now ;)).
I don\'t really know exactly how strong 坏蛋 is in Chinese (although I do know it\'s an insult). If you need any help translating it, just let me know how strong to translate it to, and I will do so.