For the upward bind, try using a bigger loop, and get the thing to swing up and let go fast. Get it swinging fast, the loop will catch more easily.
For the skin the gerbil, its your hands. If you have smooth hands, the string will slide smoothly. What you’re doing when you skin the gerbil is this:
You’re not pinching the string, it is just doing it naturally because the string is stuck to your skin.
To get rid of that, keep this in mind.