What are the most important interventions that Google Maps accepts on the road network?

You can add missing roads.

If you need tips on adding roads please see
https://www.localguidesconnect.com/t/how-to-add-roads-on-google-maps-helpful-topics-not-only-for-beginners/483627

Naming unnamed roads and paths are rarely approved.

I undid the solution as my reply was not really a solution.