Yours is actually one of the most decent ones I've seen in this website.
Tempo: Fast, not much of 'balance position' and more of 'driving the body forward to generate more momentum' here. I like it a lot
Arm action: I'd like to see the rear view on this aspect because I can't tell how much 'scap loading' (aka pinching of the pitching shoulder) you are getting. Anyways, I like your elbow-y arm and relatively short arm action, which I think is very deceptive.
Finish: I can see you trying to 'go over the wall' or 'get an extension', which I am not a fan of. However, Carlos Gomez's (one of my favorite personels when it comes to mechanics) concept of extension being beneficial to pitcher to get 'percieved velocity' also gets me thinking also. I'd like to see an aggressive finish (try seeing Edinson Volquez pitching) if your goal is velocity. I don't see a violent recoil of the arm during the deceleration phase, but try to 'bury your shoulder' all the way down till the end
Overall, good stuff