@luthluth: How would he go about doing that? Kamui won't get close enough because Kizaru is far to fast for that.
That's what I said. However if he could possibly get him in a genjutsu it might be possible. But still doing both would take planning and might be very taxing if at all possible for Kakashi.
@GamaSennin: We know man. Many of us were or are on vine too.
How can Korra hurt her? that is easy. Any attack that lands will hurt her. She is not Naruto or Killer Bee who can tank a lot of power. She can heal but her actual durability is not very high.
Also Sakura does not know kage bunshin nor does she typically have explosive tags.
1 punch is enough to finish Korra yes, but she won't get that punch in. Korra can fly and has much greater power at long range. As long as they don't start very close to each other, it's Korra's win. Sakura wins only in close quarters.