It's hard to tell with your videos, try to slow them down. it looks like you have excellent mechanics.
What you do well:
- It appears you do a good job staying closed and leading with the hips, not an easy task.
- you also get good early momentum, good lower half use in general
- appears you have hip - shoulder seperation, very good
- good front leg extension
NOW, the only real reccomendation I have is about your throwing arm. You bring it up extraordinarily early. You do an excellent job of keeping it back until it's time to throw, however if it's not too uncomfortable I'd say to change that. You arm shouldn't be going out into a cocked position until front foot strike. Late arm swing/action also helps generate Velo. Another reason I say this is you (like me) use a range of grips. Holding your arm out gives the hitter time to see the ball, and know what you are throwing. Yes, some are successful with what you do, although I would definitely change that if you can.