You can enable multiple users on Android and it is supposed to keep all data separate I think, but it will be a long time before they stop offering a physical card.

Don't give your phone to the police. Don't use biometric security.

Use physical copies of insurance, registration, and license, no matter how hard they try to push digital equivalents.

Once your phone is in a cops hands, unlocked, courts have ruled that they can look at anything they like, and it can be used as evidence.

Edit: https://arstechnica.com/tech-policy/2012/07/its-legal-cops-seize-cell-phone-impersonate-owner