To the first point, she did overcome the injury, after she incapacitated him long enough to do so. The hit wasn't meant to kill him or anything, it was meant to put him under Body Pathway Derangement. And even then she sent him tumbling a few meters. That's pretty strong for being severely weakened.
Second, I'm not sure if you were directing this at me or not, but the previous post was an explanation as to why it wasn't plot no jutsu.
Third, I really wouldn't call Kabuto a lower rank than Tsunade. Jiraiya even said that Kabuto could fight on Kakashi's level if he had to, and Kabuto was enhanced with a food pill at the time as well. He was far from a low level opponent, and Tsunade had been out of shape for years, they made a point of making that clear. Even still I'm not saying Kabuto is stronger than her because if not for his knowledge of her fear of blood he'd have gotten his skull smashed in.