"if I correctly understood what I did read, the transform faults are usually relatively small faults that can allow two tectonic plates to move away from one another"?

No, transform faults are strike-slip faults, faults like the San Andreas fault in California or the Alpine fault in New Zealand. Motion is lateral.

Transform (strike-slip faults), convergent (thrust faults), and divergent (normal faults) boundaries are the three fundamental plate tectonic boundaries.

"Vertical tubes"? "Zipper being opened"? Not exactly.