To some fans, those moments when Sakura punches Naruto are not comic relief, they're annoying moments.
As to when Sakura scolds Naruto because she cares? I don't think it's entirely the truth. In real life, I get scolded and have been scolded all the time by people who don't give a d.amn about me. They scold either because I disobeyed a rule, and because I got them in trouble because of it because they're too scared of the higher ups or because of the consequences or whatever, much like how Sakura scolds Naruto. In Sakura's case, she doesn't want to defy Tsunade or her team leaders order, but Naruto on the other hand, is willing to do that. It seems that it pisses her off, maybe out of of fear or maybe out of envy, because she's to frightened to think for herself and do what's right without getting the OK nod by the one's in authority.
Take one of the latest moments in the Manga as an example.
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Naruto hears about Jiraiya's death, he yells at the hokage and then leaves the room. She was about to scold him for leaving. Don't tell me she's feeling sorry for him, because she doesn't according to her face expression in that page, it looked like she was more worried about the consequences Naruto's outburst had for herself. She was more scared at Tsunade at that time, then to understand Naruto's feelings.
Those Soldier pills you mentioned, it's still doubtful whether she was doing it to help him get stronger for Naruto's sake or for her own. Remember, she was willing to betray Konoha along with Sasuke before he timeskip. For all we know, she could be helping Naruto out of selfish reason, to get stronger so he can bring Sasuke back to her.
She's not like this only in the fillers, but also in the manga ^.
And Kiba is not annoying to me, he considers Naruto a comrade and sees him as a worthy rival. He also treat him a lot better than Sakura does.