How would you define it?
I'd probably factor in things like price, food quality, service quality, and the look of the restaurant. If I'm going to be spending more on the meal than I spend on electricity in a month, it's probably fine dining.
Requirement to wear a suit and tie?
Only if you're a man (or identify as one). If you're a woman, a dress probably works just fine.
Some monetary limit?
I'm thinking anything over $50 per person is probably going to be getting into 'fine dining' territory.
Five course dinners?
Probably. Of course, I can get a 5 course meal at McDonalds. "Good evening sir. Tonight, we have a delightful fruit parfait with strawberries and blueberries, followed by Caesar salad. This is followed by a honey mustard chicken wrap. For the entree, we have an Angus chipotle barbecue sandwich, served with hot French fries. For dessert, we have a fudge Sunday."
Amount of serving staff?
This I'm not so certain of. Yes, many expensive places have more staff, but I've been to some very high-brow establishments with only a small staff. If they handle everything effectively and with that certain element of class and sophistication, it doesn't seem necessary to have 4 waiters per table.
Sommelier?
Yes. I'm not a wine expert, and if I'm going to be paying a great deal of money for a dining experience, I'd like at least one person there to point me in the direction of the right wine.
Amuse-bouche?
Must... not... make... amusing.... joke....
