(mostly cosmetics), what price range that it must fall into at that condition (for the purchase price) and/or what the maximum LTC to ARV must be (in other words the purchase & rehab numbers must not exceed 65-70% of the ARV, the lower the percentage of ARV the better).

For clear evidence, you may want to consider an air quality monitor specifically noted for detecting a range of smoke types.

Most of my clients buying STNL or MTNL stay in certain price ranges.

It consistently achieves 95-100% occupancy as a short-term rental, with nightly rates ranging from $350 to $550, generating substantial cash flow.

Personally, I've seen cash flow yields ranging from 10-18%, with plenty of potential for even more.

I am covering utilities for the 1st floor and garden unit (for a 3-unit MFH rental)Any recommendations for a programmable thermostat where I can lock appropriate temperature ranges?

Price ranges from $100 for a 1 and $25 for a 5. 

4) LTR projections range from $1600, which is from bigger pockets rent estimator to about $2500 from looking at comps in the area.  5) Top properties do about 10 to 15 grand more potentially, in 50k+ range which we would be happy with.

With a rate for a first mortgage today in the 6-7% range something like this probably is going to be close to or in the double digits. 

Quote from @Min Zhang: Hey Alan, I have seen areas like Cleveland and Dayton with COC ranging from 10-18% and Columbus is around 8-12% with strong growth.