Thanks for the replies everyone!
I feel a little instable in my squats and it is true i put all my pressure at the heels, that's what i thought i was supposed to do. I put the pressure on the mid-foot next workout and see how it works out.
About the vertical path of the bar, i know it is not 100% straight down but i really tried to do so. I always try and stay upright in the squat while maintaining a straight back. My "long" torso makes it hard not to have the bar travel a bit forward. I don't really think it's that long though, the camera angle sure does make it look longer then it is. The camera angle also makes it look like i go forward more then i actually do, although i still have a slight forward movement imo.
I will also try a wider stance as suggested by some people here.
And about the shirt, i only did that because i wanted a clear view on my back
I had some back pain after the previous 2 squat workouts so i thought it might be that my back was not straight enough or hyperkyphosed/lordosed. I did not have any pain in the video workout though.