The other $21k was closing costs that you won't ever be able to get out of.My mortgage is $520k principal, $31.5K for repairs...A new roof, termite treatment, and bunch of other little things.

Conventional might be more like $5k over an all cash if all contingencies are waiver.Its important to note that the escalation of an FHA/VA is not the amount the seller will realize as their is often lender required repairs and termite treatment thats going to take a chunk out.

As soon as any of those reach a year or so of ownership they now qualify for 1031 treatment. 

I was going to do a SERIOUS OZONE treatment but then just opted to do duct cleaning and the complaining stopped after that.I'd make some attempts like duct cleaning to help and then say it is what it is...Also, has the tenant identified any specific area where the odor is coming from?

@Sam Dogen Income itself is not a qualifier of a property for 1031 treatment.  

Many people live here short term as travel nurses or for treatment at the hospitals.

Our son was recently diagnosed with a chronic condition that requires very expensive ongoing treatment. 

We did everything listed by others above -- Repaint the entire house with 3 coats of oil-based kills, empty the house and scrub it down with smoke killing cleaners, repaint cabinets, replace all fixtures and appliances, full ozone treatment -- It got better in the beginning but as time passed the smoke smell came back. 

Before you take any action, first consult a CPA to confirm the tax treatment for your specific circumstances

In this case, your depreciation recapture, if any, would be taxable in the year of sale, and your capital gain can be pushed into the following tax year under Section 453 of the Internal Revenue Code (Installment Sale Treatment).