I plan to have a structural engineer inspect and make a plan.

You may need to file documents with the city to let them know it isn't a primary residence (tax purposes) and they may require rental registration and/or inspections. 

@Andrew HaneyNational Property InspectionsBrady Home Inspections Those are my go too choices.

Here is what I am seeing in the Gatlinburg market:  The buyers generally right now are "all cash", and they are waiving inspections and appraisals so that they can get a deal done quickly. 

We agreed subject to inspection and them removing the lower unit tenants so we could live there.

During inspections check everything and have bids on the items you mentioned plumb/electric/furnace, these need to be professionally done.

They should give you the best inspectors and attend the inspection if you can't be there.#3  You may want them to go do a quick visual inspection of the house before you make your offer....they may be able to keep you out of trouble before you even get started.#4 They can provide you comps for both the purchase and rents, and perhaps verify rents for you of current tenants.#5  They may be able to provide location expertise and inside knowledge of the area for you....the good, the bad, the ugly.   

In retrospect, I should have personally gone the home inspection route...

We went under contract for 25 units total, but after inspection, dropped 9 that had severe structural issues we were not willing to take on.

As I’m sure you now know, you should have released the money in draws After you had phases of the rehab inspected, so you knew your money was being used to improve the asset you had as collateral.