A script can be run when you first access the layout:
Enter Find Mode 
Set Field [YourTable::PrimaryKey ; -1 ] --> specify a value that does not appear in any record
Set Error Capture [on]
This will produce a found set of zero records.
If you select the arrow option for your drop down list, it shouldn't deploy the value list automatically when it gets the focus. You can also edit your tab order to include a button object as the next object in the tab order. The button can be hidden from view and or set to "Hide when printing".