Contract Status = Canceled/Finance Rejected - Won't allow job completion date to be entered

Create a rule in the coding that if you disposition Contract Status as "Canceled" or "Finance Rejected" it won't allow you to enter a Job Completion Date. The field can just be greyed out?

OR

Is there any way to trigger the following action: when you disposition Contract Status as "Canceled" or "Finance Rejected" it will give you a pop-up asking if you want to delete all "Not Complete" Production activities (like the system does when you are moving an inquiry from lead to job).  When you say yes, it does NOT add a job completion date.