There is a button in the upper right corner that lets you switch between cockpit, HUD and Outside View. You can have more then one P-3 in the air, but thats up to the Mission Designer. You can only fly one P-3 in a mission and cant switch.

As for the registry part - you export the contents to a .REG File (which is basically a text file). And the content of the registry you export is saved in certain way, and whenever you import it written back into the registry.