I do not understand the suggestion you make "...to minimize relationship/data maintenance by relating "Resources" to "Incidents" (or adding an auto-filled field as filter).." probably I do not get the whole picture.
Can you share a screen shot of the current relationships?, you can get it selecting "home" in the app you talk about , the select "App management" an then the third option "show relationship diagram" .
Ones the relationships are correctly created you can achieve all the questions you have.
I suppose you already used the help in QB by it gives you some advice about how to set it up correctly a many to many relationship.
here one link
https://help.quickbase.com/user-assistance/?_ga=1.50342057.1068101511.1485456111#many_to_many_relationship.html
