Can we agree in saying the oil system is a closed system(sealed)?

It is not.

Engine oil lives in the crankcase. The crankcase is not sealed. It's vented to relieve pressure from combustion blow-by. Oil vapors are sucked into the intake, burned, and leave out the exhaust.

Also, a tiny bit of oil makes it past the piston rings, and is burned in the combustion chamber.

Many cars lose up a quart of oil between each oil change.

Likewise a little of combustion material (soot, fuel, exhaust etc.) from the combustion chamber also reaches the oil.

The engine is constantly moving, and the metal parts rubbing against each other, wearing down. These metal particles are also picked up by oil.

Can we agree in saying clean oil never loses its viscosity??

Nothing is forever. But it will last a long time in a sealed container.

Can we agree in saying the purpose of the Oil Filter is to remove dirt from oil??

Of course. If by "dirt" you mean any kind of contamination, including metal that wears off the engine itself.

Anything larger than approx 10 microns. (width of human hair is roughly 80 micron)

when it starts getting dirty to change the filter and NEVER have to change the actual oil.

This makes no sense. Oil gets dirty (for the reasons explained above). It passes through the filter over and over and over, and it still comes out black. So what makes you think that changing the filter will suddenly make the oil clean. It doesn't matter how many times you change the filter, the oil will remain dirty. Anything smaller than the filter mesh size stays in the oil. The filter is only designed to pick up PARTICLES. It has no effect on compounds that are DISSOLVED in the oil.

Oil also undergoes chemical breakdown. It reacts with heat , and the various substances in the engine. It also undergoes shear forces that thin it out. Some molecular bonds are broken. New ones are created. By the time the oil is used up, it no longer has the properties it started out with.

You can verify this for yourself. Cook a cup or so of fresh oil on a heat source. You will see many compounds vaporize and come out of the oil. After a few hours, it will turn dark. If you pour out the cooked oil and fresh oil side by side, you will see that it has lost its ability to flow.

i have heard using 1qts. ATF to 4qts oil helps keep engine interior clean is this true??

That is something people were doing ages ago.  If you use good oil, and change it regularly, you should never need to "clean" your engine interior.

No, we cannot agree on any of your long laundry list of incorrect assumptions.

The engine oil system is never a sealed system. Even properly designed and built engines in brand new cars consume a little bit of oil. They need to, in order to keep the top piston ring lubricated, it's just a very small amount. A half quart every 5,000 miles is relatively normal. Divide the quantity of lost oil by the number of RPMs the engine made over 5,000 miles. It's really tiny but it's still lost. Higher RPMs also make it more difficult for the piston rings to clean the cylinder walls as they go from top dead center to bottom dead center on the power stroke. They weren't designed to function optimally at high RPMs, like a NASCAR or Formula 1 engine is. Even then, NASCAR teams still tear down engines and replace internal parts in between races.

For changing oil filters, as @MMJ says, the stuff that turned the oil black is dissolved in the oil. The filter can't remove that, or it would come back out the amber color it was when you first changed the oil. The oil's detergent will stop doing its job when its cleaning capacity is exhausted and you'll have sludge start to build up. Sludge doesn't allow oil to lubricate parts properly, and eventually leads to engine damage. A refinery needs to recycle the oil by re-evaporating it in a fraction distillation tower to remove those dissolved impurities and unwanted hydrocarbons, like gasoline. That process is similar to distilling water, only much more complex. You can't keep reusing Tide laundry soap and laundry water in between wash loads and still have clean clothes come out, right? It's the same concept with motor oil. 

"Clean" oil doesn't remain clean after it's in the engine. The first time you turn the starter and the engine fires, it's getting exposed to tiny amounts of unburned gasoline, broken down residual hydrocarbons that were left behind from the previous oil, possible crankcase moisture, etc. All of that slowly changes viscosity and thins the oil over time. Heat also causes more volatile hydrocarbons in the oil to evaporate and go into the crankcase ventilation system to be burned. Loss of those lighter hydrocarbons occurs very slowly, but gradually reduces the oil's viscosity. That all reduces the oil's ability to do its job over time.

Posted by: @kevin516

Do i need to prove my point that FLUID OIL NEVER LEAVES ITS SYSTEM PATH??

Can we agree that this old topic has been hashed to death? Can we agree that you don't have a point?

Posted by: @kevin516

I've ran engines past 300,000 miles without actually changing oil

No you didn't. You are a liar.

Posted by: @kevin516

Do i need to prove my point

You don't have any proof. If you did, you would have posted it by now.

This topic has gone beyond stupid, and no good can come of it.

Topic closed.

you say its never sealed...i say if it isn't sealed you would lose oil thru all kinds of leaks.

oil sits in the pan. flows thru the system (without leaks) the engine liquids never leave the engine except the micro amount that is burnt or thru a leak...hence it is a (closed system) just as the a/c is. the cooling system is also a closed system...unless it leaks. a leak cause low reading when checked. cooling system pressure testing shows if there are any leaks.