Atheists claim ignorance is not proof of God
No, Atheists claim the do not believe in a god or gods, that's the only claim atheism makes, any thing else and you're into a different subject.
but we have to ask WHY we are ignorant We have to ask WHY we cannot understand these things.
You are make a leap in claiming that just because something is unknown that it is therefore unknowable, that is most certainly not the case.
The answer is it is impossible for there to be no God.
Wow... A baseless assertion of the impossibility of the non-existence of god... how original.
There has to be a God because if there was no God this would violate the laws of science because entropy would not let the universe be in the state that it is.
Ah the old 2nd law of thermodynamics. Your "god" could not possibly figure into physics for the following reasons...
1. The 2nd law of thermodynamics states the entropy will increase in a closed system, and while the universe as a whole is believed to be a closed system, individual galaxies and star systems are not. The current state of the universe is resolveable through physics without having to invoke any god.
2. Your "god" couldn't be responsible for the current state of the universe because, as you have claimed, it is both unknown and unknowable. But if such an entity were to act on the universe in any mesurable way, which it have to do to magically prevent entropy as you claim it does, then such a being could be known as it's actions on the universe could be mesured and quntified.
If there is no God, then how do we explain the things we don't understand?
We explain things through research and experimentation, through mesuring actions and their reaction. What you seem to be claiming is that "god" just magics information into the minds of random people.
Why are there so many mysteries?
Because the universe didn't come with a user's guide and knowledge must be gained through trial and error, correcting mistakes and altering theories as better information becomes availible.
Not a single ones of your "reasons that "god" must exist" are unexplainible through science alone without having to invoke a "god". All you've got is one huge argument from ignorance, claiming that just because you personally don't know something that therefore "god" must have done it. And it's all couched in the arrogance and self deception of someone who thinks they have all the answers because when they encounter something they do not understand they can justplay the "goddidit" card and remain blissfully unaware that they are blissfully unaware.