It’s up to the employer to decide on what qualifications they set for any position in their business, right?
If they decide in their experience that a credit check makes it less likely they’ll get a thief as a new employee, then they should be allowed to ask for permission to run a credit check on an application. Of course you can refuse and go look for work some where else.
Again, it’s my personal information. Should they have access to medical record too?
Sure, and if the employer thinks an interview with the candidate’s ex wife will give them an accurate picture let them at it.