Do patients with a clear reason to be in pain, like pancreatitis, still need to be on a pain contract?

Yes. "clear reason" does not guarantee proper use of medications. Even cancer patients develop addiction. Everyone must be monitored and therefore opiod agreement is necessary.
Without question. Every patient needs to have a consent to narcotic treatment in place. In my state it is the law.
Yes. The pain contract is an agreement between the physician and the patient outlining safety issues and proper use of medications. It is also used as a means to educate patients about the medications they are using. It sets out what is safe and proper use versus unsafe use and what can the patient expect of the physician providing the medication. When it will not be provided, it prevents misuse.
Yes. There are many reasons for a contract and i encourage you to talk to you prescribing physician about them.