Sorry, everyone. I assumed that your rental system works like ours, in that it doesn't involve any lending of money. They actually pay AHEAD of the month in which they plan to occupy the premises. If they don't, then they don't have the right to do so and they're out. It's crazy, but it seems to work here. And I don't really have to worry about credit ratings.
Obviously, allowing someone to use your possession is a risk, an impossible one to perfectly quantify. But with the idea that everyone knows an exception, I care more about how someone treats something they use a lot than whether they owe the IRS money. I've known people who have never committed a felony and are still bad tenants. Crazy world, huh?
I could get behind a manager like the one DT or creek talk about. I do have a handyman that I just forward all maintenance complaints to. I just can't imagine paying him an additional 10% (the going rate here) to make sure I get my rent check each month. That part isn't very complicated. I guess it might be if it were part of a complicated loan scheme involving credit checks.