It may seem obvious at 1st but if Madara get's the Rinnengan then it's not so obvious because he looked kinda young vs Konan & who knows he may give though's eyes to some else & that person may be youngNumber four should be obvious as even Naruto knows it. It's Sasuke. He's the only "young" man with powerful eyes. Kakashi is rather young, but he only has a powerful EYE.
On number one. Madara could also be bullshitting. Madara has a PhD in Bullshitology.