Hey Peter - Great video!
It's always tricky when someone is fortunate enough to have a coach, because my initial instinct is to always trust the coach 100% - Perhaps they haven't pointed things out yet, because they don't want you to overthink etc (fix one issue at a time and so on).
So I'd just be a little wary of that!
That being said, I think there are a couple of things you could change that would instantly make a difference, without being drastic, though provoking changes.
1. Bend those knees 😁
Get lower on all shots if you can, it'll really help.
2. Forehand technique.
You've already highlighted this, and I bet being able to see yourself on camera has already helped a huge amount? Generally people play very differently in their head, to how they actually play in real life!
It looks like you hold the bat quite tight, with a bias towards "coming around" the forehand shot a little bit, which will add side spin to the ball.
You then come right across your body, often ending up near your left shoulder.
The minute someone gives you a heavy backspin shot, that ball is going straight in the net if you do this.
Instead, try and get more of the power from the legs and torso, and when you do the cross court forehand, try and rotate your body (whilst bending your knees) much more, so your technique stays the same.
On those forehands you were doing at the start of the video, you don't really want your bat going too far past your eyeline - That extra power you are trying to put in is currently coming from your arm (causing the extended stroke), and not the legs, torso.
But look, it's amazing you've got a 1-2-1 coach, your drills look solid, and you'll improve huge amounts in a short space of time with how much you are playing.
Looking forward to the progress videos, and subsequent "Rocky Montage" this time next year! 😁