It looks like I “may” still qualify for a partial exemption based on those 18 months. 

Type doesn't matter.What gets people confused sometimes are the terms "like kind" and "qualified use". 

And as @Basit Siddiqi said, you would also have the opportunity to put the portion of gain from the investment side of the duplex into a qualified opportunity zone. 

Not sure how you get proof of no bite history, but if your insurance company doesn't have problems with either breed, go for the first candidate who applied and was qualified. 

Any advice on how to quickly track down a qualified GC in my area with both experience and appetite?

Hard to qualify if you have a W-2 job. 

The study identifies with forensic engineering detail the immediate Bonus Depreciation 5, 7 and 15-year personal property class lives qualifying portions of a building that are normally buried in 27.5 year residential or 39 year commercial categories.

Crazy idea - How about asking your tax professional instead of a bunch of people on this blog that have no clue about if you qualify for RE professional status?

It seems like these documents are intended as a bonus for purchasing the book (kindle version is only $10), so I probably shouldn't pass them on, but I'm wondering if anyone else who has these forms have run them buy a qualified attorney in Georgia to find out if they are legitimate here.  

It is true that does not apply to investment property, but what happened was that first time home buyers that did not qualify for a home loan were trying to circumvent that Dodd Frank rule by saying "oh, this is a rental property" (wink wink) and then move into it...basically creating a no-income verification loan.