Is there a easy way to make it so that you cannot close a sales order that has a dependent Item Fulfillment record? Any ideas?

You could make a saved search of Sales Orders using the criteria of either Status = Pending Billing, Partially Fulfilled, etc OR Criteria of Applying Transaction.Type = Item Fulfillment THen use that Saved Search as the criteria of a workflow where you use the Remove Button Action to remove the Close button

Genius!

Not sure if you need it but here's a in depth look at the remove button action that we wrote

I appreciate you. Thank you.