I am pretty sure the base state isn't 0K, it's whatever the average temperature around the object is. If you have a universe that is 10^4 K everywhere, then objects will tend to that temperature. Because the earth is actually quite hot compared to 0 K, your fridge very much is constantly using energy to keep the extremely hot outsides from warming the inside. It would get easier if the earth was colder.

Yes, over a long enough timeline this is true. Usually people are interested in cooling things sooner than the death of the Sun.

Neat trick for when you want to cool something for free:

Just wait until the heat death of the universe.

I feel like this is technically true, but in reality it only works like this in the void of space.

The energy I'm spending is to counter the molecule vibration transfer that's being done (against my food's will) by the sun and everything else in the space around my fridge.

I am ready for some physicist to pop out of the tall grass and explain how wrong I am.

No, it is not, your premise is false (in our real world. TM.) but your reasoning is good.

Energy does not vanish, you need a process to remove energy of a system.

Think in the planets orbiting the sun or the energy contained in a damm with millions liters of water. The energy is not dissipating itself, it is constant, forever.

So as long as the system is not disturbed, keeping the system in the same state is energy free because you only need energy to alter the system. Even of the energy distributions is not evenly balanced through it.

Disclaimer about the real world

Keeping anything at any temperature different than whatever it's interacting with takes energy. Hot or cold.

Why would you assume the natural state of a 'object' is absolute zero?

Atoms are surprisingly bad at removing heat. Being hit with slower atoms and transferring that energy ((like newton's cradle with mismatched swings opposing each other) transfers energy much, much faster than what happens naturally in the vacuum of space. Most spacecraft have more of issue with overheating than freezing. The rate at which radiation is emitted is very low when you get to sub-human temperatures. There's also tons of heat sources around us in space, so the last few degrees are so, so hard to shed.

Keeping a fridge stocked increases the thermal capacity of the coldness. Air falls out quickly and is subject to rapid temperature change when the door is open. Keeping a bunch of solid/sealed masses in there will bank the lack of heat. You'll likely lose more air and the falling not-so-cool air will impart heat into your 24 pack of beer, but you'll have a bunch of distirbuted cold objects to re-cool the air once the door is closed instead of relying on air circulation alone. Instead of raising the air temp by, say, 5 degrees once settled, it'll only go up maybe 2 degrees - much better for food storage. But the fridge will still have to re-cool those beers, too.

It's good that you think about this stuff. It is a sign of an inquisitive mind. And you are so close to the truth.

But... You literally have the ability to look this stuff up in seconds.

https://en.m.wikipedia.org/wiki/Heat_transfer https://en.m.wikipedia.org/wiki/Conservation_of_energy

Well, "fill your fridge/freezer so there's less cold air inside that can be replaced by warm air when opening it, then it does need less energy to cool down again after opening" is true, but the reasoning… No isolation is perfect (and certainly not that of affordable household fridges) so there'll always be warmth getting in that has to be moved out again. Cooling only doesn't require energy if surrounded by equal coolness.

But keeping things cool itself doesnt need any energy

My electric bill disproves this statement. Otherwise, why would we need electrical devices that remove heat from things?