Thank you for the replies!
The sc pulley is fine, no wiggle and no clicks or sounds while spinning either.
I don't have anything to take my wheels off (let alone a jack) but it was an overcast day so I could see well enough from the top down. I took both belts off, and I was able to turn the balancer right and left with one hand without the middle part turning (turning it left hits metal, and I didn't try turning it as far right as possible). It doesn't wiggle side to side but I think it's pretty certain that its separated. So I guess that diagnoses the issue entirely?
