this is way off topic to my original post but here goes my opinions from my own perspective:
Although I could add some factors to point in your favor. From what we know about Madara he seems like the type that couldn't care less about eternal peace. But there is also the possibility that he promised his brother something, and he wont go back on his promise, lol, but in the end all humans are selfish.
From my understanding of Madara's history, Madara did want peace but only if he was the Dictator why make a truce with the Senju otherwise ?
For Obito. Yes in order to manipulate him a plan like the moons eye plan would surely be useful.. But it is a bit strange he already started mentioning it for him even before he barely knew who and how obito was. Of course he might have learned through zetsu spies through reading his memory, so can't neglect it.
If someone told me that their true intent was to either be the following : SO6P, Immortality, i would be questioning "whats in it for me?"
i mean you wouldn't tell someone that you just met that you want to manipulate them into helping you with your true agenda right ?
So of course you tell them something different so they would be enticed into helping you right?
Regarding the Naka Shrine Oro should also know most of it now, since he saw everything Kabuto did, and Kabuto just confirmed "their" theory. Another fun fact is that Kabuto says "Lord Orochimarou and I made a hypothesis based on our research, and now you have proved it" or something like that as I remember. Which is interesting cause why mention Orochimarou to Madara, if Madara didn't know him? There is definitely something to it. It would also explain why Oro joined akatsuki to figure out their goals and how far Madara had come. I'm also pretty sure Oro and Kabuto knew for a long time that Madara was not Tobi.
The Uchiha were the only clan able to decipher the Naka Shrine which was in segments/stages; the control of the Kyuubi was common knowledge for those with the normal Sharingan. But the information deciphered whilst reading the Naka Shrine with the MS is limited and can still be speculated upon as well as i can only think of 2 possible people actually capable of reading it currently:
*Sasuke
*Kakashi (doubtful since the Naka Shrine is a Secret Uchiha spot)
The first Uchiha to actually decipher more than the already common knowledge would have been Izuna and Madara through the MS, and quite possibly more information was deciphered by Madara after obtaining EMS concerning the Rinningan and the Juubi
Orochimaru and Kabuto would have only theorized and speculated from historic events/myths through experiments/analysis left behind by Madara
And seeing that Kishi has this whole Uchiha brotherly love going i agree i would love to see Izuna beside Madara again ruling together myself although i know that their Era has long passed by.
This is just my opinion and view on what I've gathered so far from Kishi's story telling.