The fuck. She's one of the best tsunderes ever, because she grows as a person. Her reasons for hitting him are often understandable, even if it's not always warranted. Because I can understand why she's doing it, generally, as well as the fact that her frequency of resorting to violence has reduced drastically over time, I feel like she works very well. The best part is her reasons for resorting to violence have evolved over time, to the point things that would have set her off earlier in the story have a point where they no longer do so, which is part of that aforementioned character growth.
I have frequently been observing moments as I have read this story where her frequency of violent outbursts has gradually reduced due to her deepening love and comfort with Raku. (even when she does hit him, she frequently apologizes for it, nowadays, almost right away. Like this instance, where she clearly shows and expresses concern for his well-being after the fact)
One of the best examples, to me, of how she is one of the best tsunderes is that very first hot springs episode, where she was doing everything she could to protect him from being discovered. Yes, ostensibly it was because they'd both be shamed, but she likely was already starting to care about him at the time, as well.
In my mind, a well-written tsundere has distinct evolution and at least a somewhat comprehensible reasoning. Even if her violent outbursts are triggered by frustration or embarrassment, or some other factor or even combination of factors, it should always be generally predictable for a given stage of her character development.
Chitoge has gotten to a point in this story where she very rarely hits Raku, and the more they understand each other, the less likely this is. Unfortunately, they're hitting a rough patch while Raku struggles to understand his own feelings, let alone hers, so things are starting to get more strained again... but I imagine it'll clear up again as narrative progress dictates.
Edit: And, wouldn't you know it, after a series of unavoidable coincidences the same day, they manage to laugh, apologize, make up, and then continue to have an amazingly fun night out. How can you not know they are destined? Despite hardships, they still manage to make things work.