I think you're getting mad at the wrong things. I got the impression that Tsunade was just using most of her strength to attack. Using pure brute strength to train Sakura without using her speed, techniques, strategies, etc is plausible in my opinion. Remember how the focus of the training was dodging (because medical ninja shouldn't get hurt)? It sounds to me like Tsunade was attacking with attacks that would seriously hurt/kill if they connected, in order to help Sakura with her dodging. Its not a perfect explanation, but it is plausible as far as these shows go. Remember, it still just a shounen series. Remember how many times Naruto (and others) have gotten beaten up and seemed destined to lose, only to have some revelation about friends/family/etc and then have a miraculous victory. There will always be that type of thing in Naruto. It's that type of anime. You just have to take it with a grain of salt (or bottle of vodka).
That said, you should be mad at how the writers and animators are sitting around laughing at all the people who keep watching. They can put in a fifth of the effort on an episode compared to the average anime, and it is STILL the most popular anime running right now.