Do you want to beta test my Ship Editor? Let me know of any issues or exceptions that you get?
Unfortunately, the resulting ship.xmls won't be readable in FC 1.6 (without converting the weapon tags back to weapon numbers) and you will have to correct the weapons for all of your ships within the editor (via dropdown box) as the editor doesn't automatically convert weapon formats between FC 1.6 and FC 1.7.
Obviously, we are still a few months or more away from an FC 1.7 release, but this will give you a chance to update your fighters, capships, and weapons.xml preemptively.
Edit: Oh and the rotation matrix to angle and back works perfectly.