Buy a vacant piece of land close by and offer to store his stuff for free until the house sells. 

This year I'm maximizing business deductions and I was thinking of buying a sizeable gift card to one of the big home improvement box stores for my business for materials for investments next year. 

Is there some service other stores which I can use so I have a PO Box but I get the mail forwarded to my home address.

We have a property in Chicago, Portage Park area that we are interested in rezoning and developing into a multi-use property with 3 commercial stores on ground level and 9 residential above.  

That a landlord will hire PMI or Renter's Warehouse because they've heard of them. 

A warehouse, retail or an office building - yes.

Subdivisions, RV parks, resort-style developments/venues, storage, warehouses, small office, etc.

They sell them at the big box stores.

You've got a lot of green/granola/alternative types and type stuff and stores and restaurants, and you've got a lot of downsides to that -- homelessness, anti-government/anti-vaxxers/homeopathic types.

I have family members, friends, and even a next store neighbor who are RE investors.First, my dad.