So Jiraya found out who Pain was before he died, and scribbled the answer on the frog's back. Did they reveal or hint yet at who Pain is?

Also, Itachi seems to hint that Madara is weak and could be beaten. However, Pain seemed invulnerable, yet he took his orders from Madara. How strong is Madara really? Even in the past, Madara was beaten by the First Hokage, and he never was able to take on the Leaf village by himself. He only made an attempt after controlling the Nine Tails.

I don't think Madara can possibly be stronger than Jiraya. And I think Pain is much stronger than Madara, but is somehow directly controlled by Madara.