The mistake that you made, was not getting rid of those particular negative people, as soon as you either took over the business/learned of their negativity. How much you pay and how great your working environment is, has nothing to do with the fact that some people are going to be miserable, hateful or negative no matter what
No. He needs someone with good credit, as his is destroyed. Might have been a one time thing because of one client, or might be because of a string of poor choices. Do NOT, because if he makes more bad decisions, you may be the next to have to declare bankruptcy