Customizable Hook (OpenSCAD)

I needed a bathroom towel hook for my shower glass panel

Instead of using my regular CAD software I decided to use OpenSCAD and make it customizable. I've never used this software for my designs before and this is my first time “programming” with OpenSCAD. 

Might not be the cleanest code but it works (for me).
I'd appreciate it if you have any suggestions or feedback that helps me to learn the OpenSCAD language :)