But let me get back to the atheist = more immorality thing. I think its best to give an example here.
I find your example somewhat faulty, because you don't take into account how your view of morality and ethics would change when you became an atheist. You might very well find that you gained a new moral sense to replace the "god-sense" that previously held you in check.
I think people are moral by habit, and I doubt that atheism would cause a big change to your habits. If you're in the habit of only getting into fights some of the time, then I doubt you would find yourself in many more of them. (And fighting isn't necessarily morally wrong, anyway, although the way you do it seems a little reckless.)