@Bryan Stocklas I am not familiar at all with Illinois contracts but there are a couple of things you've mentioned that I am not understanding. You said the seller is claiming the panel is properly working so it doesn't give you the right to terminate, what if you had found a severe mold issue? The house would technically still be functional, would they expect you to close? You also mentioned the panel isn't properly wired, that alone should be enough for you to cancel the contract unless it gives the seller the option to correct it.
You also wrote the attorney's letter says “Neither of the cited references constitutes a qualifying deficiency which would be a legitimate basis for termination of contract”, did you cancel based on the financing contingency or the inspection? If your contract was indeed contingent upon financing, and you can no longer obtain financing, then this seems pretty cut and dry.
I agree with the majority here, they're very likely just blowing smoke. I'd get your realtor to do some work and if he/she isn't helping then get their broker involved.