My question is, because of the particulates in the air causing respiratory issues, is there anything legally stating he has to actually finish the flip before renting?

I'm Air Force.

I would highly recommend Mitch Barela, the owner of Barela Heating and Air.

@Derrick GrahnToday was the Inspection day part of due diligence.I used Chad Cooper from AZ property inspections, the Inspector came out this morning and we walked the inside of the units inspecting under sinks, closets, A/C for cold air, Bathroom, water heaters, attic space, roof, main on/off outside water valves, washer & dryer rooms.Inspector recommended that I have the sewer lines scoped and because of the age and the property is on a septic system so it must have the system inspected by an ADEQ certified and qualified Inspector.none of the water heaters have on/off valves or Temperature/pressure-relief (TPR) valves which he said they should. he found some mold in two of the units because of 2 water heaters.

Class C rents in Tucson tend to be skewed when comparing properties with evaporative cooling and central air.

I bought a duplex, that I completely renovated and now I live in one side and air bnb the other.

I want to increase the rent to $1500 which is still under market and offer them free air conditioner if they sign it within 10 days.

If you do have a pet free unit though it is my understanding that you have the right to have it returned in the same condition so it seems fair that they are responsible for carpet cleaning and I would go for air duct as well. 

Some of my places don't have central air, just window units. 

I would also look at a duplex , triplex or 4 plex so you can Air BnB if allowed or have the other tenants help pay the mortgage while building equity.