Good thing Naruto is an animated character who, if necessary, can survive bone-shattering falls, being crushed by boulders, impaled, decapitated, or crumpled like a paper bag. It would suck for him if he had an actual, corporeal form.
And now you know how this happens.
I don't think her hitting Naruto will ever stop. What I mean is that if Naruto steps out of line. Then he has be punish. There is no Kushina around to discipline him. That is why Sakura character has played a major role in Naruto's life. When Kushina was not there to pamper him. Sakura has gone out of her way to keep Naruto in line like a mother, sister, and a spouse all together; versus Hinata never done squat but hid behind the corners and watched Naruto suffered dejectedly his entire life, and the Pain arc doesn't make up after all these years she could have hold Naruto's hand.
That's why NH will never work. Hinata is unworthy and undeserving to have Naruto-kun when Sakura had made him into the man that he is today. He did stated that in the second bell training excercise, that he's not going act stupid infront of her ever again after whinessing her chakra punch.
Her hitting Naruto is a good thing. She won't hit Naruto on the head for something minor. This has been proven when Naruto was throwing a tantrum to Tsunade about a D-rank mission the beggining of part 2. Sakura could have smash her first into his face. Instead, she has chosen to playfully choke hold him.
The team seven Reunion, Sakura could have trample Naruto when he has fallen asleep next to his comrade when he was poisoned at that time. She quickly came to realize Naruto was being series when Kakashi told her Naruto was poison, and she never stumped him the way her face indicated.
The only reason I see her relentlessly beating Naruto the way she did in Part 1 is Naruto hitting on another girl besides her. Kishi till this point has never gave Sakura competition for Naruto's heart, so where does all this anger will be vented on? Sadly Naruto has to pay the price.
But this is all in good light, because Sakura is displaying her anger to us readers that clearly She does not want Naruto to date and become intimate with another gal, which She is teaching him a lesson not to label himself as an open territory to the female population. But sadly also, this has only been proven in the fillers arc, OVA, and movies.
But to sum it up, there is nothing to fret about their "future" romantic relationship. There won't be domestic violence inflicted by Sakura if Naruto continues to be the mature gentleman that he is. On the other hand, acting stupid for an example: "Sakura-chan, can't wait till I get you pregnant 'again', so that your breasts will become enlarged once again."
Okay lol... That's just asking for it. I know it's a natural to some men to rouse their mate mate for fun just to get their blood boiling. Sometimes it leads to good laughter and kinky reaction from their female companion, or a Sakura castration type.
But I wouldn't worry because Naruto will make Sakura the happiest woman on the the when the get married.