Well, firstly let us define what is "God", what do we mean by that word. My definition of the word "God" is taken from the Vedas.

janmādy asya yataḥ: the Supreme Person (God) is that one from whom everything has emanated.

This very word "everything" in this definition means there's no other God.

If you can prove that such person cannot exist, please do it. Otherwise, let's accept such definition of God and continue our research.

You see design in cancer?

Yeah, I see it indeed. I see the purpose of sufferings and I see the great design in them and His love also. Bitter treatment is meant to cure you, but still it has bitter taste. So you're asking me what design in this bitter taste? Why is it bitter, not sweet? Because your understanding of love is wrong. You consider sweet things as love. And this "sweet" things is what pleasing your body. So your logic is if you love me, you must satisfy my senses, you must make my life comfortable. And if you don't do this then you have no love for me. This is wrong understanding.

For the sake of real happiness we sometimes have to experience pain and discomfort. And that one who's leading us to the real happiness although meanwhile is causing pain, he loves us. That's love. Love is not material comfort. So the reason for cancer and other sufferings which we experience here is actually love. But due to our misunderstanding of what is real happiness and what is real love, we blame God and dare to claim there's no sane design in what's going on.

this is nonsense

Why you're saying it is nonsense? How have you known who's your father? What's your personal experience? Or when you're reading a book where an author claims that there are electrons and protons, you're just believing his words consider him as authority, isn't it? This is kind of faith, nothing more. And you're getting knowledge by listening. Not by direct perception or by speculation. So where's nonsense here?