There is another way to explain everything that Madara has shown so far. Even his deception when he tricked the first in believing he was dead.That's the only question that I don't have a solid answer to. Hashirama would make sure to check if Madara was dead, so there would be no real way for Madara to play dead as Hashirama leaves the scene. If Madara did indeed use Izanagi, you have to consider the consequences as well. An eye loses vision permanently, and considering Madara's Eternal Mangekyou Sharingan, I don't know whether he would make such a large sacrifice. But I suppose that in choosing between life and doujutsu, he took life. So if Madara did indeed use Izanagi, then the collective power of the tailed beasts will go towards strengthening his eyes, so that he may resurrect the Jubi and become its host - and then project his eyes onto the moon, Mugen Tsukuyomi. The infamous Moon's Eye Plan.
Well, if Eternal Mangeykou Sharingan is a form of sharingan that never loses it's "light", can it cast Izanagi without being rendered useless?
What if his space time jutsu is nothing more than izanagi? remember that danzo showed more or less that ability when using izanagi. attacks passed through him. And with madara one can consider that he would be more adept at it than a non-uchiha, allowing him to use it more freely and with greater ability. It would explain the eye we never see (it's beeing kept active with izanagi the whole time), the ability to pass through things, being impervious to attack, the inability to use other jutsu (his chakra is being used constantly in izanagi) and it could explain how he's still alive (it's a genjutsu that allows you to shape your reality, so he can be shapping his so that it keeps him alive, and that's another reason to keep the hidden eye always active).
what do you think?