Im going to New York in April, when you enter the country and go to passport control etc, do they scan passports and get up personal information (credit history, criminal records, address etc?) If so, what would stop them allowing you to enter the country?
The machine readable bit of the passport just has the same information as your passport does anyway, only in machine readable form.
I'm not sure whether US immigration have access to UK criminal records, though I guess it is possible that they could do through the police national information service.
The official line is that if you have even been arrested (not even convicted) for anything other than a minor traffic offence then you need to apply for a visa and, depending on the offence, you might not get one - I'm not sure what the criteria are. This applies even if your conviction is 'spent'.
However, your address or credit rating won't have any bearing on whether or not you are refused access.
When you fill in your card on the plane it asks questions such as have you ever been convicted, have you ever been sectioned under the mental health act, cant remember the specifics or anything but its that kind of thing. They dont have access to you finances or anything, they just ask the reason for you visit, what your occupation is blah blah blah. I know there is something relative to if you have ever been convicted but im not sure on the details so If I were you I would check out the USA embassy site as it basically tells you everything with regards to things like that, just to be on the safe side!