Hmmm, I think this sounds more like a "God needs to prove there is a God" than a "why doesn't God communicate with us more", no?
One would do nicely and accomplish both.
Evolution is a fact, God can no more disprove evolution than God can disprove gravity. You say that God can prove that he created everything, well, are you sure about that? I mean, what proof woudl be enough for you?
Because the proof may just be that he set events in motion and allowed for the chain reaction to do what he knew it would always do.
He's god, right? he can harden the hearts of some when it chooses, he should be able to figure out what would be proof enough for me. Unless he can't, in which case there is something he can't do which means he isn't god.