You will need resources in place to service the property, especially for tasks that need immediate attention. 

The only pros I can see for a shipping container is the mobility it offers. 

What other networks of people I should be asking these questions in or resources that you've found especially helpful?

I personally chose to seek after a firm that was doing deals but not offering a coaching program.

Alternatively, set aside one or two boxes of things that family might want that you can offer for anyone to go through....believe me, it will save you some grief in the long term with your family.  

Its a bit overwhelming to begin this process, but I know there is a wealth of information and resources with BP.

You may want to approach the contractors and let them know you plan on putting in a claim and see if that prompts them to offer a compromise. 

I am surprised you can put a 506b offering on a website that is public facing? 

Plus, the fully finished walkout basement offers endless possibilities.

You can't count on believing that the family member will not produce a handwritten lease (real or not), or other paperwork & tactics, to throw a big old wrench in your initial/expected timeline.You CAN expect that if they see you as the big old rich/developer/bad guy enemy, they will do as much damage as they can, and drag their feet as long as possible.See if you can feel out what the relative actually wants/ needs, connect/come prepared with info on resources for local "housing help" options, etc (perhaps), and figure out what you can do to solve the problem (cash for keys with an incentive for quicker move out timeframe?