Don't forget, she also slapped Amanda. And scratched up Dex's face when he attacked Galen in Season 6. She also lunged at Ben when she found out he "triple-crossed" her, though he was able to ward her off. Plus, in Season 9, didn't she start throwing things when she got mad at how that one mercenary guy ran his business, and she had to be tied to a chair in the next room? And during the flashback, when she realized Roger Grimes never loved her, she pulled a gun on him.
Seemed she was already pretty violent.
Personally, I think it should have been *Krystle* who became more violent over the course of the series, though mainly towards Alexis. Take that one really low comment Alexis made about Blake not being able to tell the difference between having sex with either Krystle or Rita. That should have earned her a beating that would have smeared her face in blood and dirt (cuz Krystle would have dug Alexis' face into the driveway).
After all, what's one of Joan Collins' most famous quotes about our two favorite divas? "Krystle fights with her hands. Alexis fights with her tongue."