OK, here's what I've learned. If you make gun pods a selectable ordinance they will drop off like bombs when armed and "Drop Selected Ordinance" is triggered. Also, the only reason bombs work is that their DP file gives it a bomb effect when it hits the ground or an object and breaks. If you give the gun pods a "gunstation" and "guns" entry in their DP file, the program has no way of linking them to a cannon trigger.
So, in a nutshell the idea of gun pods as a selectable ordinance option will not work. Maybe if by some miracle MS gives up the source code for CFS2, we can make all kinds of great things happen but until then it's all trial and error.