That is bullshit, they are just trying to scare you (and understandably the stick seems to be working and, well, whatever works right?). I highly doubt they are actually liable for anything just because they have a patient on benzos and methadone. That happens all the time, and I have heard that threat all the time - it is simply a strategy of scaring the patients to keep them in line.
Be careful with taking pregabalin. Taking higher doses of it (>600mg at a time) regularly is almost guaranteed to lead to complications (including seizures). I found alternating between gabapentin and pregabalin really helpful while I was on methadone dealing with some shit, so perhaps you could try to find a way to get access to both?
Gabapentin, in my experience, is far more benign than pregabalin. The upside to pregabalin is that tolerance doesn't build so fast (though it builds faster than a lot of people think). Just understand that you can't take pregabalin with little to no worry of side particularly harmful effects like you can with gabapentin. They are two very different beasts in that regard.
I'm curious, as I LOVE SB, why do you say that? They have a great clinic there (one of the best I've been to), but I don't know much in terms of what they have as far as social support goes. I imagine it would be better than LA, as this is a rather tougher town than coastal cities in central/northern CA. But I just don't know anything about the scene there.
I hope you feel better ASAP!