Hello and welcome to Wattflyer.
I'll jump in here as I have become the local expert on the DJI Phantom and other controllers. I'll start with a disclaimer, my opinions may not be the most common, but free advice is worth every penny you pay for it
Balancing props is important to any RC model. On the Phantom, its not always needed. Once you put the props in the balancer, just use a fine grade sandpaper on the TRAILING EDGE of the prop (like 220) on the heavy side if needed.
Next, dont use the WiFi on the Go Pro, you wont have any DJI troubles with that. Use the GoPro wifi when just playing with the camera.
I would disagree on buying another quad to 'learn on'. Fact is, the Phantom is crazy stable and reliable. Its like a Segway for the skies. It does all the work for you. If you spend the money and time learning on a 'toy', I dont think the skils you want for the Phantom really translate. I have had equal amounts of pilots with and WITHOUT R/C skills buy, own and fly the Phantom. Total RC newbies (i.e. photographers) are now loving the Phantom.
Balancing the motors is completely un-necessary. With balanced props, simply use the GoPro case that comes with the camera, not the worthless frame that comes with the Phantom.
Graupner props are also IMO a waste of time and money. They are good props yes, but I see absoloutely no advantage to buying $8 props (cost in my area) when the DJI props are near indestructable, and CHEAP. ( I have Black DJI's on the rear).
In this video, I have NOT balanced the props, but am using the GP case:
Do you see any jello? Nope. I have since however balanced my props, just 'cause.
You will see once you launch the 'assistant' software, there are no reasons to change anything. You can activate I.O.C. but do that only after you are good flying it around, otherwise sometimes its hard to grasp the concept of Intelligent Orientation Control.
I have mixed feelings on Gimbals. When I am flying FPV, I like to have a direct visual cue as to pitch, yaw and roll. When doing aerial video, a gimbal is sweet to have. I have it on good authority that DJI will be filling this void soon. For me, I'll wait until they offer one.
And flying out of the box IS that straight forward. Calibrate your compass, wait for GPS to acquire, and FLY MAN FLY.