A tenant in one of my duplexes moved out under the cover of darkness late June.

We will not allow animals or smoking, which will limit our tenants but also mitigate associated risks. 

After this I am totally in the dark!

Also if it is just paint and a little cosmetic stuff unless you got a smoking deal you may not have enough equity to refinance out into a favorable long term conventional loan.  

My husband just went down in our tenants basement to replace the smoke detector and discovered water marks from a very obvious recent flooded basement.

Toyota, Honda, or some old piece that you could trade Grass Cutting for the summer and a Carton of smokes for, at some point or another may need a jump.

I have a code enforcement inspection each year and the biggest issue is usually smoke detectors and any other safety violations.

And two of the units don't have carbon monoxide or smoke detectors.

Yes I get the whole "dark art" perception that comes with the 1031 exchange. 

It has been proven to me over many years that is a dark and dangerous road.In our leases, it states that if the maintenance issue (lets use clogged toilet or sewer main) is a result of normal wear/tear or lack of owner maintenance, the charge rightfully belongs to the owner.However, if the tech pulls out a toothbrush or Barney the Dinosaur out of the drain, the full charge belongs to the tenant.