I check county records, tax records, current appraisal from the local municipality, and check for comps in the local are with respect to the properties condition. 

It might not make a difference to you, but your tax pro and bookkeeper will hate it. 

My only income is 1099s, which I write off a majority of it to lower my taxes.

I bought these properties cheap, had them fixed up and not have they appreciated a lot that also generate a nice tax free cash flow that goes back into my IRA to be redeployed into more properties.This is a huge tax free money maker. 

No, it was a single 30-day stay.Proof is not required when you file your taxes.

You won't have to file a state tax return with Tennessee as they don't tax rental income.You likely want to work with a CPA who understands the different state tax laws.Good luck in your search

It sounds like you are looking for an employee as defined by most taxing bodies.

Taxes are high in Carbondale.

Is there a tax advantage if I do a cash out refinance of one of the rentals and buy the primary out right?

As my avg rental period is <8 days, and I have <14 days personal use at the property and believe I can meet the material participation test, this should be a non-passive activity.Specific Questions on Material Participation:1) Do hours logged for material participation in 2022 include time prior to placing the property in service (i.e. first half of 2022)?