How about use the PI Camera module instead? No wireless mess and much cheaper than a GoPro. I'm not even sure the GoPro video stream is accessible outside their proprietary app.
There are a lot of tutorials online on developing computer vision with the PI.
However, it sounds like the K.I.S.S. solution for you would be a backup camera or something so you can see whats happening behind you instead of relying on CV (computer vision) especially if you don't have the software chops to take on the CV challenge.
The reason I shied away from using the Raspberry Pi camera module is that I live in what is essentially a wet hole in the ground in Yorkshire, is consistently wet and when it's not wet it's damp and when it's not down its usually flooding. So that's why I thought the go pro would be a better choice.
The Raspberry Pi is going to be the ideal machine I think to do the heavy lifting hopefully, and the main reason I am open to rely on CV is that there is nowhere to fit a screen on the front of my wheelchair. I tried streaming wirelessly from a go pro to my iPhone and the battery life was absolutely abysmal.
Maybe if the CV detected a problem it could make a fit bit or something similar vibrate to alert me to a problem, different numbers of vibrations were different situations etc etc. Although it is ENTIRELY possible I'm overthinking this!
There are a lot of tutorials online on developing computer vision with the PI.
However, it sounds like the K.I.S.S. solution for you would be a backup camera or something so you can see whats happening behind you instead of relying on CV (computer vision) especially if you don't have the software chops to take on the CV challenge.