I understand your frustation.
One of the Unreal developer told me he is working on a better documentation.
I don’t want to offend Epic, because Unreal Engine has got 16 years of technology and an estimated value of about 1 million dollar.
I will leave Unreal Engine too, to find another engine, maybe C4.
But I will continue to follow Unreal Engine.
Please Epic, as a Christman gift (even on Xmas 2015),
write a book about Unreal Engine! I would be in a hurry to buy it 