I work in a restaurant and I've been to a few around to see how others work. Trust me - you do not want to order anything from any resturant right now. Ironically, more fast food places seem to be safer, since employees prepare food in front of the customer will wear a mask at all times.
Not in the back of the kitchen. It's already deathly hot there, and being forced to wear the mask for an 8 hour shift is far more bothersome. To be clear, I'm not saying that as an argument against wearing a mask, because everyone absolutely should wear them, but the cooks I've seen do not follow this rule. They will wear it with the nose uncovered, they will take it off for stretches at a time, I even saw one where he cut a hole into the bottom of a mask so it looked like he was wearing it properly at a casual glance.
Near as I can tell, if a cook can get away with getting around a mask, they will.