There's potential to add paid laundry or extra storage facilities in the unfinished basement - which might increase your returns a bit.

I thought that due to the rise in e-commerce, we could buy these spaces and convert them into "last mile" storage facilities for online retailers.

given the current situation - Self storage (couple options) - Dialysis centers (couple sets of dialysis centers)I would estimate that this half of the investment would generate a 8-11% IRR long term.

Landscaping, paint, fresh concrete, etc can dress up the outside with relatively little expense. 

Doors without damage, fresh coat of paint, if damaged ones can't be repaired inexpensively, replace-they are not that expensive for just the door. 

Same is true with outside water spigots, garbage disposals, storm doors, storage sheds, and garage door openers. 

A friend of mine just approached me with a deal on a self-storage business.

Although I did pass, I feel like I would have done much better if I would have immediately taken those exams while the material was still fresh in my head. 

Or is the single family one parcel, duplex is another, maybe the garages are on a third (although not sure what value these have unless you plan on renting as self storage)

Really well designed spaces with great storage and flow - small but comfy outside space - etc.