That rust is pretty bad...as you said, was definitely back east. Rust isn't an issue here in AZ (unless there are parts up north where it snows where they use salt instead of cinders). Know that rust near structural junctions can pose some major safety risks...as those spots are much more likely to 'give' when there simply isn't the material there that is supposed to be.
AZ won't pass with a CEL. It might be something simple...you can take it to a local AutoZone/Checker and they will pull the code for free. Do you have the car? Are you in AZ?