You sound very authoritative, but some of your numbers seem odd. Do you have a source for your 30% rent figure? Most sources I see suggest a much lower number: http://www.4hoteliers.com/4hots_fshw.php?mwi=1661
Sorry, you are right. The rent figure is for a cafe, and even that might be high. And I read it in an article from a cafe owner who lost his business. Maybe he was paying too much rent.
I'm not a restaurant guy but I am known to be able to read income statements with my eyes closed :)
Assuming the GP was generalizing "Rent" to include all expenses associated with the physical plant and presence, the sample income statement linked is close enough to that 30% number.
But your call on whether my assumption is too generous :)
A pan may be a fixed expense but it is to a significant-extend used up at the rate that people consume food, so it's not really "free" if fewer people are in the restaurant. Only "rent rent" and wages if fewer people in the restaurant.
Essentially, economies of scale might be possible in operating a restaurant but the place would need to be organized for this from the beginning - the simple ability to get people in the door is worth less than a large share of the receipts.