I don't really see any way for her to even hurt him, let alone kill him.
I don't even think a Plot no jutsu or Death Hax no jutsu will save from screwing up royal.
I think what most people were p***ed at was that she didn't seem to understand the difference between their power at yet she still goes gallivanting off saying she should fight him instead of Naruto.
Congrats Sakura, you have officially joined the list of top ten anime/manga douchebags.
One of the many meanings of the word douchebag:
(An individual who has an over-inflated sense of self worth, compounded by a low level of intellegence, behaving ridiculously in front of colleagues with no sense of how moronic he appears.)