These videos are amazing for new robotics builders! I found these videos helpful for aiding my newer team members.
I'm really glad you decided to do this series. Feel like there isn't much out there to really introduce teams to really getting started with VEX. One thing I really think you should have hammered down is the importance of lining up the tabs before you screw it on. It's not enough to make sure they are aligned in the end. if you ever screw it on misaligned, you will ruin the bearing by bending those pegs. In locations with high torques, that might not matter, but if you're working on something like a flywheel, it's game over. I think this is critical knowledge for rookies to know.
Also, doesn't nylon completely screw up the grinder wheel? I think it might be better to use it on a belt sander or like you said, a Dremel.
gear ratios
@PastranaDigital