1.- No Sakura cannot beat Sasuke even when she's being serious and Sasuke's blind. Sasuke took on Kakashi even when he was blind, making an even match. There's no way Sakura can get close to him. Sasuke could've killed Sakura twice, but Kakashi and Naruto came to the rescue.
2.- Sasuke now has Eternal Mangekyou Sharingan. He doesn't need anything but that. Not to count he has great speed, great taijutsu, great shuriken jutsu just as Itachi, great sword technique, AND A BRAIN. Sasuke is a genius. Sakura only has barbarian strenght and healing abilities, plus her spirit is easily breakable and she's afraid of many things, and most of her decisions are DUMB.
3.- Sasori is NOWHERE close the STRONGEST Akatsuki. The Strongest Akatsuki we could say is Madara, followed by either Itachi or Nagato. Sasori is not that strong, he's just annoying thanks to his poisons. A swift person would be able to take him out. Probably Kakashi, Gai, or even Naruto.
4.- WE HAVE SEEN SAKURA HIT NARUTO WHEN HE DOES SOMETHING STUPID OR PERVERTED, AND NARUTO ALLOWS HIMSELF TO BE HIT. If he was serious he'd dodge. Sakura isn't compared by any means to Naruto in the battlefield.
5.- Sakura has been asked to be serious many time. We've seen how she fails most of the times.