Be sure to keep all records, including his communication by text/email and any online marketing.

I was initially excited because I have an awful tenant who refuses to even communicate with us. 

This will help in developing a Focused communication path and prevent asking/answering the same question twice.A. 

We have tried everything to settle this in a friendly manner, however in the fall the tenant communicated verbal threats numerous times.

But in the near future out town will be rolling out high speed fiber optic communications. 

Hopefully that will show him you are serious and he will communicate with you

I have now been sending Certified LATE RENT NOTICES each month, including full balances due.Tenant will not communicate with me, and had turned down a very gratuitous Cash for Keys proposal when this all started. 

Please also keep in mind, the borrower would be under bankruptcy protection, so you must be careful in how you communicate with the borrower and/or their attorney, so as to not violate the automatic bankruptcy protection.Your post didn't indicate what jurisdiction the bankruptcy was filed in, you should probably talk to a creditor rights bankruptcy attorney in that jurisdiction.I practice in Indiana, so my answers below are based off Indiana law/practices. 

Very swift process, amazing communication, etc.

All they do is take 10%, own your listing and are only communication relayers.