All IRA based plans are required to have a custodian to administer and report on the account.

The day any Real Estate Commission devises and administers an integrity exam I will be the first one saying #teamgetlicensed

Don't need to incur the costs to establish and annually administer unnecessary legal entities, don't need to incur various filing fee costs like CAs $800 franchise tax fee which would kill the profitability of most of my SFRs, I don't need to worry about my entities being pierced because of I failed to engage in a lot of meaningless formalities, keeps my overall record keeping and tax returns cleaner and less costly, don't need to deal with the growing trend in various states to disregard what are perceived to be ersatz legal entity protections, how many more do you need?

Not you.You can administer the IRA's investment, you just cannot benefit.  

He has no heirs and nobody to administer his estate once he is gone.

You need to turn into a unit selling operation, and line up property management, handle sale disclosures, administer a good HOA situation for newcomers, on top of all the other stuff your business does.

One thing you should be concerned later on should you purchase the parcel is if one of the heir's files a competing Notice of Petition to Administer Estate.The probate petition will have a different case number competing against the primary estate. 

We just found out about a notice of default that was just recorded as well.The seller is the court appointed administrator administering this Estate.

All IRA based plans are required to have a custodian to administer and report on the account.

Are there companies or banks that will administer the “loan” for me, such as collecting payments, calculate interest and such.