Is this deep background check again a US thing? In Germany it's even unlawful to ask potential employees if they are pregnant. It's essentially discrimination. Maybe some HR will check your social media accounts and search on Google for you but generally police records (at least my experience in IT) or even health records are not requested (or against law!) unless it's a high responsive job like e.g. becoming a police officer or maybe military.
Asking potential employees if they are pregnant, married, plan to become pregnant, have children already, etc... is illegal under US law as well. Common German practices like asking for a photograph on an application or CV or asking about a prospective employee's religion are also usually illegal in the US, as it's pretty hard to think of non-discriminatory reasons an employer would need that information.
Asking previous employers about their experience with an employee, however is not illegal. It's usually not illegal for them to say something negative if it's true, though some businesses are conservative about what they will say out of fear of being sued for slander. Accessing public court records or news stories about criminal cases and using that information for employment purposes is usually not illegal. Asking prospective employees if they've been convicted of serious crimes is usually not illegal.
I think I may have confused it with Ireland or Northern Ireland where there's a legal mandate to keep track of it for anti-discrimination reporting.
It does seem to be conventional to include one's photograph, age, sex, marital status, children or lack thereof and place of birth on a CV in Germany. It's not clear to me if it's actually problematic to exclude those, but it's my impression that not following conventions tends to not go over especially well in Germany.
I even remember learning to include my parent's jobs on a CV but thankfully that is gone for good. The things you listed are still common with variations depending on the industry. More often than not you can exclude them without negative effects but sometimes those are still seen as important information.
What are you talking about? At all (german) companies I ever worked at is was common to request a "Polizeiliches Führungszeugnis" (essentially police records or the lack of such) first thing during the trial period. This is absolutely common, maybe you just forgot about that?
Not sure at which companies you worked at but outside certain fields it is not common and actually illegal as the Führungszeugnis may contain entries irrelevant to the job. Exceptions include working with children/youth, public officials, security guards, insurance, and some positions in the field of logistics.
