He did not hit off the backfoot every time. And it is not inherently wrong to hit off the backfoot anyway (Nadal do it very often for ex).
But your hip rotation could be more pronounced, you could stand closer to baseline on those balls, the follow through is not complete somtimes, esp on backhand, the accelleration looks stiff/tense, the footwork could be more fluid.
But to conclude, nothing major wrong in my mind. You just need much more practice with good sparring partners, developing the areas i mentioned. (that is for groundstrokes). then Serve, return of serve, volley, dropshot and so forth, we dont know that yet.