The worst part is the foundation.

A 401k does not require a custodian or a third-party administrator (TPA), and you don't need an LLC to have checkbook control for your 401k.

It is a triplex so I don't anticipate it being a massive frat party type of issue.

If he agrees to let the other person move in, make sure you put that in writing and have it signed by all parties.

From one of our sales, We were also advised that if this property sells to a third party at a sheriff sale, and we cannot provide the department of revenue inheritance tax lien certification, the Allegheny county sheriff will not issue the deed until they receive a copy of the lien certification. 

Not saying they are bad deal but that one party always has the the win win scenario. 

Use a 3rd party servicer in case the person still have some debt in the property to pay directly to the mortgage company.5.

I think you will run into a related party issue rather than an LLC issue in regards to the 1031 exchange. 

Payment may not be made by third party checks.

I think the only two issues that I think about as I contemplate signing on are the speed with which they have been growing, and the fact that they are just now moving to being vertically integrated -- their property management and renovation teams are all in-house now -- not 3rd party like they used to be.