i say Zetsu helped out! He is the land himself. He's probably the one that found Obito as well.Okay, first: The byakugan was said to be the stranoest dojutsu in regards to Insight.
This means that the user can see the chakra networks "nodes". points where, if damaged, can change the flow of the chakra network. With this knowledge, the Leafs greatest Taijutsu is born.
This alone does not surpass the Sharingan, because the sharingan consists of 2 parts. It has the ability to see the flow of chakra, but not the nodes. It will give each chakra a distinct color, so they can differentiate between people. This next part, the byakugan does not have, making it inferior. It can copy techniques, and will eventually evolve to give you special jutsus.
The only time it has been said that the byakugan was superior was because it can see the individual nodes. It, however, is an inferior dojutsu.
Obito did lie to sasuke alot. I never said that madaras brother willingly gave his eye to madara. I said that madara's eyes possessed him, just like itachi said, and that possession made him take his brothers eyes.
And about madara, you are correct. It is very strange that he could do that. Maybe, he just passed on through as a civilian. And anyone who tried to rob him or whatnot, died. Also, we know that there are extensive underground passages. Orochimaru used some, but that probally was not the extent of them. He only had to pass through the Land of Fire, and then into Amegakure.
Another strange thing is how did Madara pick up Obito? The Gedo Mazou is in the Mountains Graveyard(way north of Land of Fire). And the Tenchi bridge was in Kusagakure. (West of Land of Fire.) And he said that Obito landed in one of his tunnel. (http://www.narutobase.net/manga/Naruto/602/5) Sooo, does the Tunnel really go that far? And does his attaching string thing that keeps him attached to the Gedo Mazou really that long? Then it is completely feasable that The tunnels could go all the way to Nagato. And he Really could get there While still attached to the Mazou. After all, Kusagakure and Amegakure are neiboring countries.
And why would Nagato revive Madara in that condition? We don't really know the extent of that power. When Nagato used it, he had no chakra left, and it killed him. And all the souls that he took in that battle were returned. If he was focusing on just one soul, he may have been able to restore Madara back to the point where he only had Uchiha DNA. To before he battled Hashirama. Then, Madara would just kill Nagato, and take his eyes back, and implant some of Hashirama's DNA that is stored with the Gedo Mazou. And he would be, him again.
Here is a Map.