Yes you can do that, just filter on the basis of the Update(boolean) line item and create a saved view. Now use this saved view for the import. You will get only the checked items updated in the system.
You cannot do that in this module. You would require a different approach for that.
Create one more module dimensioned by Employee List. Now import the Data (Text and number) with respect to the Employees. Now reference that data here in this particular module using a LOOKUP on Employee ID.