I'd have to disagree with Orochimaru being weaker in comparison to the rest of Akatsuki. I can say Itachi would be the only one Orochi may not be able to handle and not because of Orochi's inferiority complex towards a jutsu copier; but rather the perceived insane power Kishi has built Itachi to have. While the Akatsuki are working to control all the bijuu for their own use, it's somewhat been implied that Orochimaru already has something more than human inside of him. I wouldnt say he's merely learned jutus which have allowed him to take the form of a snake in various ways. There seems to be some power within Orochimaru yet to be revealed.

And to stay on topic, if Kishi were to tie up the Akatsuki and Sasuke retrieval in this arc, as many loose ends as there are, there are some major ones that would need to be tied up before this manga could end ie. Sasuke reconciling his quest for revenge against Itachi, and Naruto becoming Hokage as mentioned. The fans would not be satisfied if it were to end after this arc.