Yes. There’s a reason some of the most often needed groceries are almost always at the back of a supermarket.

Yes, because that's where the refrigerated warehouse is usually located: in the back of the store, to make it easier and cheaper to restock shelves from behind. By comparison, at least in the US, green groceries are almost never in the back of the store.

I don't understand "cost center". Everything is a cost center except the part where you physically acquire the money. Surely both marketing and customer service are invested money that hopefully increases your customer base down the line? What's the difference?

I suspect the real reason that the panopticon is kept separate from the customer is to avoid creeping people out.