Currently I'm looking for some kind of methodology, software or app, that I can use to manage the properties, which will allow for another family member to step in to my role relatively seamlessly if I were to pass in the future.

For me as well as the seller.First, you have to define Sub to financing.Do you mean the reckless kind where you overpay for a property, take over the financing and borrow from others to cover closing costs and holding costs when you have no money, no credit, no income, no reserves and can't tell a warranty deed from a deed of trust and you close on the kitchen counteror do you meanbuying below market value, already having a nice income, having reserves, using escrow and title, already understanding the due on sale clause, have done a lot of creative purchases and know when to use and when not to use creative finance and how to recover if something goes amiss?

Quote from @Ashish Acharya: @John Gillick To fully defer taxes in your 1031 exchange from the $450K sale of development rights, you must reinvest the entire amount into like-kind property.

There are all kinds of everything.

I plan to kindly follow up with collecting.Trust but verify - I looked it up & there was a news story about itAnyone know of any resources out the there to help him in the short term with rent? 

What kinds of policies do you think might help ensure ongoing affordability as Texas continues to grow?

These kinds of deals take time to develop.

They finally get back to me after the close date to say they need more time because they are try to cross collateralize their other properties to make this deal happen and the bank they were using doesn't do this kind of loan. 

If you provide any kind of substantial services like catering, car service, etc you will change you tax situation and no longer can file under Schedule E.

Pretty easy to make 2% or more when you're spending that kind of money.