Sakura would probably catch a Susano'o arrow to the temple, I don't think it's a good idea for her to be there. She should heal some fodders in the meantime, and let the big boys have their fight.
I can't see it happening. I feel like kishi is saving the last battle for Sasuke vs Naruto, if Naruto wins I feel like it'll be strange to see anything continue after that. That has been the major goal of the series to get him back so once/if that happens I think the series will be over.
LOL NOPE!! naruto and sasuke will die killing each other in their ultimate battle and after tsunade dies, sakura will be the new hokage. End of story!!!