The main issue: the Foundation would never ever ever ever ever utilize an SCP object in such a fashion, especially not as the primary or SOLE source of power for entire sites. Especially not when it's already known that each one of these crystals holds a finite (even if massive) charge, and there are a finite amount of them. The Foundation exists to completely cut unknowable whatsits off from the rest of the world, and if they had a choice between weaponizing 682 in a controlled way and having to go into battle with pointy sticks? They'd pick the sticks. It's what we do, it's literally in the name.
On top of that, there's a lot of tonal issues, and it seems you're trying to force a scare in places without anything to back it up; there's literally nothing here that shows anything besides "the crystals create auditory hallucinations and their power output fluctuates as potential charge drops." Certainly nothing that actually shows the presence of "monsters."