It’s not as big a risk as this person is making out. If you’re playing with low current microcontroller stuff, there’s virtually no risk. At most you’re gonna let the magic smoke out of a chip, not start a fire.
If you start getting into stepper motors and things like that, sure, but that’s a long ways from where you are today.
Very safe unless you attach razor blades to the blades.
Most small DC motors don’t have enough power to break the skin