Why Sasuke needs Orochimu?
I've made a few post on why Sasuke needs Oro to talk to the " one " who knows everything. I mentioned that the person is Madara . Why would he want to talk to the So6p sons? Madara is a founding member of konaha and it was mentioned that others clans used Konaha as a blueprint to create their own village hidden_. Which means Konaha may be the oldest hidden village. Madara is the oldest Uchiha dead or alive with the knowledge of the clan and village. Oro mentioned that there were more then one ( them) that knew everything. Tobi fills in the blank between Madada's death and the present. Tobi knows about the Uchiha uprising and nine tails attack. Also hisharama and Madara should be about 120-130 years old now. What would the sons know about Konaha when they were around maybe hundreds of years before Hisharama and Madara.
I think aloy of you read to deep into the story forgetting that Kishi's
fan base is children ,young adults and us older adults with child hearts( hence the toys, playing cards, video games, movies, anime and manga) People believe the scroll contains some super secret power up . I think it's the scroll to control Edo Tensei. It would explain why Sasuke is not willing to master it himself as suggested by Suigetsu and use Orochimaru to regain control of Madara so that he can talk to him. Madara will not sit down for a spot of tea with Sasuke to answer his life questions. He's about 105 years older than him. We quickly forget that Sasuke is only 16.
I think Tobi is a part of Madara and Oro knows it. Which is why he corrected Sasuke when he mentioned the ONE who knows everything. Why do you want to talk to THEM?
And to answer the question on the place they are going that Sasuke is formiliar with? He could simple mean one of his lairs. Sasuke spent nearly 3 years learning under Oro .