I haven't read most of the previous 24 pages, but I hope you know that your forehand swing is all arm and 2/3 of your body is working against you - probably because you try to hit open stance when you are already in position to step into the ball and then jump out of position.
Here are your pictures - the same thing happens in the video:
Look where your legs, hips, and abs are in the second picture. You have already rotated away from the ball. You are just standing on your back foot. See in pictures 3 and 4 how you have to reach to get to the ball because you have stepped away from the ideal contact point. You have opened your hips and chest when you stepped away from the ball. You can see from picture 2 to 6 that there is almost no movement of the legs, hips, and abs and you are still just standing on your back foot. There is no weight transfer and no rotational movement.
If you want to gain some energy from any part of your body below the shoulders you must either 1) step into the ball as you are lined up to do - which is generally what most pros would do in that situation or 2) as you step away from the ball, keep your chest and hips parallel to the flight of the ball until the racket is starting to move forward and use the stored rotational energy (like winding up a top) to rotate your upper body during the stroke and pull the chest, shoulders, and arm around. (Move your left foot to the spot in picture 2 while keeping the rest of your body in the position in picture 1 - you should feel the rotational stretch through your legs, hips, and core.
It would be easier, better, and more efficient to just step into the ball and swing (in whatever way you please) instead of trying to make it a more difficult open-stance shot. Open stance allows you to get to the ball 1/2 step sooner and recover back another 1/2 step sooner. Right now, you are moving the extra 1/2 step all the way to the ball and then jumping away from the ball. A good player should know how and when to hit open stance and more closed stance.