Kabuto has already proven to be more knowledgeable with Edo Tensei than Orochimaru was so I doubt he would make the same blunder he did, not to mention Orochimaru didn't even know that Minato was sealed inside the Death God so I wouldn't even call that a mistake on his part, if he had known Minato was sealed he never would have tried to revive him. I don't see why Kabuto, who knows that Shisui's eyes were taken from him before his death, would try to revive him knowing that he would come back with no eyes...it doesn't make sense. What do you mean, how can he make his body younger? They haven't explained it but he obviously did it as we see Madara as a young man instead of an old man. He can't make Nagato walk again, all he did was make Madara's body younger, and making Nagato's body younger isn't going to change the fact that Nagato's legs are injured, and his legs also lost muscle memory due to them being out of use for so long, which also screwed up his mobility.If Orochimaru would've tried to revive Minato knowing he was in death God, I see no reason why Kabuto wouldn't try a similar feat knowing Shisui em has no eyes. When nothing is missing they can be revived with all there techniques. Izuna eyes were missin no way for him to be revived with all of his original techniques, and Kishi seems to only made Madara a special edo no one else. Everything suggest he gave him the Rinnegan somehow since he didn't have it in his prime, and how can Kabuto make his body younger? Why didn't he make Nagato walk again?
-Madara is old, Kabuto revives him with Edo Tensei and he gets all of his abilities back and then Kabuto makes him younger.
-Madara is old, Kabuto revives him in his prime and gives him Rinnegan.
The first one seems more likely as it goes with everything Kabuto has already stated, how would he go about giving him Rinnegan anyway? As we know Edo bodies can be modified so making Madara younger doesn't seem out of reach, but Kabuto magically making the Rinnegan appear on Madara does. Edo Tensei doesn't even revive you in your Prime so he had to have made his body younger.