Quantum communication occurs how, by magic?
Yes, quantum mechanics has some implications that indeed appear magical with our classical understanding of the world.
Write down the measurements once, test against them forever.
You did not read the article about the non-cloning theorem, did you? If you are familiar with the Heisenberg principle and are willing to accept it as a fact, the informal proof is quite easy to understand.
You can't measure the signal without disrupting the legitimate people trying to communicate, but you have still measured the signal.
The point that you don't seem to understand is the fact, that in quantum cryptography, the measurement of the signal corresponds to a key guess in classical crypto. If in quantum crypto your guess is wrong, the measurement failed and there is no way you can measure again.
Alice and Bob measure the signals all the fucking time in order to communicate.
Yes, but they use the correct key.
5000 years for classical crypto to be brute forced? Massively parallel FPGAs (or GPUs if you're cheap) say a few weeks or months. And it's getting faster all the time.
5000 years was just an example. The time required for brute forcing depends on the key length. If the key is long enough, it takes 5000 years or more, no matter what hardware you use.
Please, learn something about ANYTHING.
No need to be rude here.
When I was saying that you should learn some basics about QM, it was because I really think it would be a benefit for you. The quantum mechanics lectures changed my view of the world completely and I'm very happy I can understand fascinating things like quantum cryptography now.
But well, you can still say it's all bullshit what I'm saying, and stick with your Newtonian view of the world. But believe me, you miss something.