@Aga, all that you have written has already happened, will happen in this arc and some are just unlikely.
Naruto and Sasuke already battled many times against each other:
- as kids, but not friends,
- as rivals, but still kids,
- as Majin Vegeta, ops, I meant CS2 Sasuke and 1-Tails Naruto,
- plus other short encounters.
They already had a final-like showdown at the end of the first part (at Vote), with a bit evil, eerie vibe. Ending the second part like the first one would be a little disappointing, I would prefer to see them go with the a good vibe, friends, rival duel, like the one in Scry-ed, or none at all. Half of this manga is about Naruto making Sasuke knowledge the MC , so it might end simply with that (after witnessing all that Naruto did from sidelines, might be enough, plus a believe that Naruto can correct the past better than him, can easily make Sasuke join the Naruto front).
The Nine Names are important within this arc, since that is what the 10-tails fears, because it gives the So6p vibe.
Kyubi chakra x Sage Mode will also happen within this arc, because you need at least Hashirama level Sage Mode to take down the current Jyubito, which means, as already mentioned, high Bijuu level chakra mixed with NE.
Sasuke will also need some kind of power up, probably the assimilation of Jyuugo, perhaps in similar manner to how Sasuke assimilated Orochimaru, quite likely resulting in CS3 that mixes well with Final Susanoo, allowing Sasuke to become a real Tengu.
This arc does feel like the last one, because every mayor and fodder player is on the board. This happens most of the time at a manga's end.
I myself would prefer Obito winning/completing his MEP and making everyone fall into the illusion (of course without them noticing) and showing everyone how the real could look like and that it's not that hard, as long as there is a will and then, give the gang another chance of breaking from it and making the same dream come true in the real world.