Ok I have several questions: Why would you hire such clumsy personnel considering the threat level of the Diclonius girl?Why would you have a cage that small and open considering how dangerous she is?Why not make the fence have a 3 meter radius just in case?And finally, why would Lucy let the glasses guy walk away scot-free, isn't he like the CEO of that facility???
Kurama says she was toying with all of them — she made it seem like she needed to use Kisaragi as a hostage in order to make sure they let her escape, when she didn't even need the hostage to begin with
She's basically telling Kurama "I killed a whole squad of armed officers, and I can kill you just as easily — but I won't, just on a whim"; she's essentially mocking him, telling him he's not even worth killing
You can see how she laughs and tells Kurama that Kisaragi's death was a wasted one, making fun of how he promised Kisaragi right before she died that her sacrifice "wouldn't be in vain"
As for the clumsy personnel — I 100% agree with you, clearly this girl isn't a threat that can be dealt with just by your run-of-the-mill police handguns, she looks like she'd need a fully-prepared and disciplined team of special ops units monitoring her at all times, maybe even more thna one team of them at that; I'm guessing their security wasn't very tight because the budget for this project isn't that much to begin with — we can see how the old government official tells Kurama that the whole operation is a "waste of taxpayers' money", implying that the government doesn't give much funds to Kurama's project to begin with, which is why the security is so shoddy