You are well on your way already. Some guys here have posted dirtier form than you have. So even though i did like you asked and the list may seem long it ain't that bad at all. Don't get down we've all been where you're at. And relatively speaking you aren't that far behind the top players in form. If you can dedicate enough good field practice your form and results will be much better during this summer. You have a good arm in power and speed. Probably in controlling ability too. That is a great place to continue from. Keep up the good work!
The final step is too long because during that step you raise the whole leg toward the target from the hip joint. That left you weight back which resulted in the disc rising flying nose up and stalling eventually. The left arm swung far from the body in the reach back and it came close to the body in mid throw and stopped in place swinging back out in the follow through. Becoming extra weight for the legs, hips and shoulders to swing around. Slowing your turning like a drag anchor on a boat. If you could keep the arm moving at least at the same pace preferably faster than the body turn from torso pointed 90 degrees left of the target to follow through you'd relieve the legs, hips and shoulders from the burden of turning the weight of the left arm. Making you faster and throwing longer.
There is more power to be generated in twisting the hips to the left of neutral in the reach back and to the right of neutral close to the hit. The same goes for the shoulders turning right just with a later timing in the turning to the right so that the kinetic chain fires in sync. Legs first, hips and only then the shoulders. You reached back as far as you can with the shoulders and the arm -to the right of the tee pad viewed from back of the tee to front. That is increasing power but it will reduce accuracy and repeatability so it should not be used in control throws. Only with open area 100% power rips.
If you could look at yourself from above you'd see that the disc did not move in a straight line from back to front. Instead the disc remained at a fairly constant distance from the body moving in an arc made by the body turning. That is corrected by allowing the elbow to lead and bend into a tighter angle. An easy method for pulling in a straight line is to stand close to a wall trying to pull close to the body and not hitting the wall.
You are straining your body hard and losing power generation and repeatability with being too flat footed. You don't have to be a ballerina tip toeing but less sole to ground contact will help a lot. Considering your ankle issues you are best off rectifying as your first priority. From this perspective it is great that you don't point your right foot farther off of the target in the plant step. The angle you use is good for control drives but once you're more light footed you can generate lots more power by allowing the toe to point a lot more away from the target. At full force i plant heel pointed at the target. That will kill your leg in the first session if you have as much sole to ground contact as you did in these videos. So please _please_ fix the foot pivot first before you start to experiment with added angles. At your own risk of course.
For a flat shot your follow through step was a little too much to the right. A sign of being a little off balance. You should face 90 degrees right of the target with the torso and the left leg should be on the line from the right leg to the target. Any deviation from this means less generated power and accuracy. It ain't a major thing but significant anyway.
Your left heel dragged on and off the ground bouncing up and down. That comes from too much speed. That meant no kicking forward at full efficiency. Less weight transfer, weight back ans slower body turning meaning less power than you are capable of generating.
Flat shots need running on the center line of the tee and planting each step on the center line. Anhyzer needs running from rear right to front left with the plant step hitting the ground to the left of the line you're running on. Hyzer is the mirror of that.