It would be nice if tags/coordinates and other elements could be marked as “obtained from a trusted source”. For example: In my home town I got some official geodata.
These elements would still be editable but there would be a short warning massage before you can change them. (“This element has been been obtained a trusted source! Are you sure you want to edit it?”)
It would be good to know if such elements would be somewhat safer from accidental/mistaken edits.