That squat is looking a lot better man. Good job paying attention to tension through out the movement and keeping up the work on those feet. Could be better but it is a lot better than what you were doing.
On the back extensions with weight try not to turn it into a row (you’re getting a little arm curl). Remember, like Murph says in the back raise video, a 25lb plate is a lot heavier if you hold it behind your head or even more a arms length overhead. Just some variations to explore next time you have back raises.