French Fries: Why soak in cold water, and if so, why a long time I have heard that, to get crispy french fries, I need to get rid of the excess starch on the surface of potatoes after cutting them. But that can't be the reason, really, because starch is actually what FORMS the crust... so my reasoning is the following: we soak them because enzymes released by cutting will quickly convert the starch into glucose, and THAT will caramelise and burn our french fries. Is that the reason why we use cold water, to keep the enzyme inactive?

If so, soaking in cold water seems unnecessary to me. Thoroughly rinsing until the water runs clean should be enough. Am I correct?
The reason why you want to get rid of the excess starch on the surface is, while cooking they will brown faster and will yield very dark brown fries, instead of golden-brown "which we all like ;)". It has nothing (or little) to do with enzymes aiding caramelization/maillard reaction. The browning happens at high temperatures, such as the temperature of the frying oil. As you have more starches on the surface, they will get darker, or even burnt.

As a side note, I’ve found out that instead of soaking, just cooking the fries in water for a short while helps greatly in getting rid of the surface starches, even more than soaking or running them through water.