I don't necessarily think you "should have bought the Vision" so don't feel like you've gotten something inferior, you're better off thinking like your next statement, with the Vision models the camera doesn't do you any good in any other application, with the GoPro you can use it for anything.
The P2 non-vision's RC works on the same frequencies as wifi.. it's not wifi just the same frequencies that's why you can't have the gopro's wifi on, or else as your Phantom gets farther from you (the RC), the local gopro's wifi can override the signal from your RC and the Phantom flies off and is lost.
so no, there's no direct control of the gopro camera in midair. If you're taking video, just start the video before you take off and stop it when you land... use editing software later to snip out the bits you want to keep, even the free gopro video software works well for that and there are plenty of free aftermarket video editors.
If you want stills, there's 2 ways to accomplish: personally I just put the gopro in timelapse mode and tell it to take a photo every 1 or 2 or 5 seconds... all you need to do is hover for a few seconds and you know you got your shot... sift through and delete all the extra pics later.
Other folks here say there's a mode where you can be recording video and take stills at the same time, but they also say those still images aren't quite as high quality as if you're only taking stills... I can't verify, I've never played with that mode I always just record video or take pics.
all you need is a couple 16GB cards, there's pretty much no way you're going to fill one during the limited flight time of a Phantom before you have to come back and land to swap batteries, just swap in a new memory card in the gopro too. 16GB Class10 MicroSD cards are like $10 these days, pretty cheap. I see 3 packs for under $30 all the time.
for actually changing the GoPro settings on the ground, I turn the wifi on and use the ipad app which makes it a LOT easier to change resolution, picture mode, etc. but you gotta be sure to turn the wifi back off before flight. You need to be careful with that of course one time I almost flew off with the wifi still on but I noticed the blue blinking light on the gopro as soon as I took off.
in the end it might be a teensy bit more effort on your part but I am way happier with the gopro version. plus if you decide to add FPV the systems you can add go much farther than the Vision's wifi fpv.
