Dont worry about his height… that doesnt matter until college & even then if he can get batters out with the right velocity there would be interest & oppty.
Staying with pitching will create many positives… stronger arm & increases his chances to make the better teams as he develops. Tie breaker on making a team will certainly go to the player who can also put up some innings on the mound.
Look up Herschiser drill… that will help with the lead leg action. He does break his hands high. Having said that the timing isnt that bad as it relates to the overall motion. My son has a more consistent break with better timing if we talk about where his hands should be (belly button to mid torso… your guy is at high chest) & also pick a spot where the lead leg should be when the hands break. For my son its well after balance point… its when his lead leg is 1 ft off the ground and already 2 ft away from rubber as it is driving to the plate.
Hope that made sense, but having him get the lower body moving first (leading with hip… Herschiser drill) & giving him a visual as well as “Feel” for the location & timing should help.
As far as the glove side mgmt… thats not my strong suit. Search some of "Roger"s posts… he has some good posts on those dynamics.
I do like ur sons shoulder alignment & glove position right up to rotation. It seems at rotation (a touch early btw) he seems to go “dead” with the glove mgmt. you’ll get better feedback from others but he does need to stablize it out in front close & above the knee and let the body come to it. Your guy seems to let it drop & dangle vs using it as key part of the release & finish.
ive found video is the best way for my son to get involved in mechanical changes… when he can see where he is at vs the goal it seems like the conversation leading up to and following go smoother.
again, keep him pitching if he enjoys it… the throwing sessions will lead to 5-10 % better arm & control down the road & that will serve him well at any fielding position.
My son made it onto one of the better squads this year due to pitching & is getting the early nod at SS due to his arm. The incumbent SS cant make the throw.