afaik you are correct and there's no way to actually control the GoPro while in flight. You understand the reason behind not having the gopro wifi on, yes? on a P2 non-vision your RC operates on the same frequencies.. it's not wifi specifcally, but the same frequencies so if you have the gopro's wifi on, as your Phantom moves away from you that gopro transmitter will rapidly become a stronger signal than your RC and your Phantom can do any number of things, best case being Failsafe (return to home auto-land), worst case being a total flyaway (LOTS of cases of this)... and believe me these things are fast it could get VERY far away before you even know what happened so better safe than sorry! never use gopro wifi while flying. I turn the gopro wifi on when on the ground to manage the settings quickly via iPad but then of course you need to turn it back off.
FPV simply lets you see LIVE what the camera is seeing.. if you're just flying around with a gimbal and gopro watching from the ground it's next to impossible to frame a shot precisely (gimbal angle, Phantom orientation, etc). FPV lets you see exactly what the gopro is seeing so you can frame your shots, but simply broadcasting/receiving FPV doesn't have anything to do with "controlling" the gopro.
indeed, you must set your gopro's settings and hit record, take off, fly around, etc land then hit the button to stop recording.
or if you really want you can take off and hover and press the button... I've done that a few times when I forgot to hit record before takeoff. watch those fingers though!
I personally went with the P2 / gimbal / gopro option because I felt like that was more flexible. I mean, now I have a GoPro that I can do whatever with when I'm not using my Phantom. With the Phantom Vision models that camera isn't any use to you when you aren't flying
