You can use layers, layer views, web maps (and apps) to achieve this.
Additionally, I am unable to give the contractors access to the GIS system
How can they update it then? You could have a webhook for a survey, but this basically means you are providing access... otherwise I assume they dial in and step 3 occurs
Step 3, office staff are not likely to use field maps as they are not in the field. A Web Mapping application with editing would be better. They can change the status.
Step 4, yes field maps is good here.
You can use any combination of layers/maps/apps/field maps to achieve the above.