@mightsprite, once she's been in business long enough to get more perks, there is a perk that makes restocking "instant". Well worth it once you can get it.
Love the look of your place, by the way. I struggle to get that grunge look when I try, you did an excellent job of it.
As for buying out of the fridge, I sell eggs, milk, cheese and fizzy drinks out of the refrigerator in the grocery store of my game and have never seen a Sim actually buy from it when playing the owning household. My other Sim households do buy from it all the time though. It's just convenient as heck.
You don't need to "restock" the items in the refrigerator, so honestly it's possible unplayed Sims have bought from it and I just didn't notice.