First, you need to open Preferences -> Scopes and create a new scope that includes only the files you would like to inspect. Then, in the Preferences -> Inspections select the inspections you'd like to use only for the files in your scope, click "Add Scope" and select the scope you've just created.
Now you should be able to fine-tune the inspections per scope.
Yes, this is possible, although a bit tricky.
First, you need to open Preferences -> Scopes and create a new scope that includes only the files you would like to inspect. Then, in the Preferences -> Inspections select the inspections you'd like to use only for the files in your scope, click "Add Scope" and select the scope you've just created.
Now you should be able to fine-tune the inspections per scope.