Choose SIM Card when entering new contacts

Seems to be an Android thing with no way to change it, see also this topic:
https://forum.fairphone.com/t/how-to-access-my-contacts-from-the-sim-card/19039?u=johannes

You could, however, export contacts to the SIM cards after they have been saved - see the topic below, especially from around post 13:
https://forum.fairphone.com/t/fp2-add-local-contacts/11858?u=johannes

This discussion may be useful - there’s some hints on how to get the time to show up by default, but there’s no way to change the lockscreen without replacing it entirely: