I suppose that's true.
I did intentionally flanderize her (using the Trope meaning) due to the Kalulu effect.
Kallen was expressing the whole fanboy/girl KallenxLelouch obsession that I've personally encountered online, which is why at the end of that sequence Kallen goes through the litany of "conspiracy theories" about Lelouch being alive.
It's a shout-out to fans in many ways.
She's hot-blooded in the series without a doubt, especially if you count how many times (and on who) she unsheathes the knife she carries in her purse at Ashford.
Kallen is certainly overreacting (and I'm happy you thought so because that was the intended effect) because of her own pent up frustration and obsession with Lelouch.
Imagine if she actually did hear rumors of him being alive, and with CC no less.
Kallen would be furious about it if it started to look like it might be true (not to the extent that I made her angry, but again there was a reason for that).
Thus Kallen begins a slow and painful process of growing up from having the emotions of a young teenage girl obessed with the "Bad Boy" to a more mature woman that is looking for the "Right Guy."

I planned this story out from the very begining.
It certainly has its flaws and mistakes, but overall it is working out the way I intended and the feedback I'm getting is better than I ever hoped for.

Thank you for reading.

And to both you azul120, and CodeGeassAddict, welcome to the forum.