Specifically for tactile techniques, I’d say wok movement and flipping. High heat and constant movement are key to good wok fried foods, and flipping in the wok is almost the only way to ensure multiple sides of ingredients will make contact with the pan. Wide spatulas generally only move things around.
Practically impossible to say. You never know how old potatoes you get from the store might be. Maybe a few days, maybe a few weeks. I’ve had freshly harvested and cleaned potatoes go months before showing new root growth on the outside, but I’ve had a new bag of potatoes have one or two turn moldy in a few days.