3. She used Umino to spy on Rei's date with Mamoru in the first season, allowing the boy to buy her a drink and think they were on a date. Umino didn't deserved to have his emotions manipulated.
This one really shouldn't count because it was early in the first season where you would expect this kind of thing from her.
1. She slapped her boyfriend for forgetting her birthday... which she never told him in the first place.
I'll give you this one, she didn't tell him or any of her friends about it after all of that time so that was a good enough reason for each of their reactions.
2. She physically spanks Chibiusa, a child who she didn't know was hers at the time. Small children who are lost from their parents need support from their elders, not abuse because of their brattiness.
You're talking about Chibiusa's debut episode right? That's not a good example at all because of all the stuff Chibiusa was doing prior to that. This "scared child" excuse that some like to use to describe Chibiusa in R doesn't really work for this episode (along with the stolen brooch episode which I thought was even worse) because she was giving Usagi problems from the moment they met, scaring her & Mamoru with the toy gun*, brainwashing her family*, trashing her room, attempting to attack her while she was both taking a bath and sleeping (which for the latter she ended up playing the victim when both parents & Shingo came in), and drugging her & her friends at Rei's shrine (which failed with Usagi). All of this trouble just so she can find the Silver Crystal which at that point, nobody knew why so what would you expect Usagi to do? Sure the spanking was harsh but there weren't many options left if she wasn't going to stop.
* - Yes, these were in the manga & Crystal too but not all of them.