Not trying to excuse Lapis's actions, but I get the impression that a lot of the Homeworld gems' willingness to hurt Steven--an eleven year old child--could also be because gems don't have a concept of "children." They're born "adult." Add that to the fact that humans are positively squishy compared to gems, and you're gonna have a few close calls.

Doesn't excuse Peridot referring to Steven as an "infestation" and attempting to squish him, (even if she was just "doing her job") but it does help explain Lapis attempting to drown Steven (and Greg and Connie) even after he befriended and freed her as a (possible) case of not knowing her own strength. Or she could've just had enough of him because he sided with the Crystal Gems.

I imagine if any of the non-CG gems join the CG, we'll see their previous actions addressed in some manner.

Also connie and she tried to kill greg, I really hope they acknowledge that she almost murdered three people in a future episode, and if she does become a part of the crystal gems like people predict It would be interesting seeing connie and greg’s reaction.