Hi RisuNeko, got to really commend you on how much you've done to try to change the situation. But now I see no other alternative than to contact the authorities.
I'd say that threatening your boss with calling might not be very productive in really changing things, might give your boss time to come up with false excuses for if they are questioned, time to cover up some things, and maybe fire/discredit you.
And if authorities are looking over your shoulder you can be really filling them in on what's been going on, give them the evidence. And with the administrative problem.........well the authorities will have different ways to address that.
I do really admire your drive to change things but sometimes that has to come from the outside, for the residents protection, for your protection.
So maybe you'll find some useful phone numbers here:
Abuse and Fraud Information How to Report Abuse and Neglect
Or at least they can point you in the right direction.

Alison