Who asks for a prospective employee's religion in Germany? Apart from church affiliated positions this is illegal here as well.
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.
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.