Also both of separate thermostats, but only the downstairs has air-conditioning.

I use the cheap air filters that you can see through.  

Even with just clean-up related costs for a little bit of water it would probably run a few thousand with air movers, dehumidifiers, pumping out (if needed cost), and mildewcides

.******* I am not a doctor or lawyer or advising anyone to go start eating popcorn ceilings or huffing asbestos******What casey states is correct, however if you are going to DIY spend money on the best respirator mask you can find at home depot, and if you are going to remove the carpets, and you want to scrape the popcorn ceilings, use a hose to soak the ceiling to make it come down easy and  to lower the dust particles in the air.

I live in the columbia area and retired air force.

Wright Patterson Air Force Base attracts people to Huber Heights and there is a new windshield plant opening near Kettering that will be bringing 800 jobs to the area in 2015. 

That's a pretty special skill.I mean, if I were trying to do that evaluation, I have to admit I would basically just be pulling numbers out of my bu ... out of thin air.  

Funny, in April I gave up my day job, which was on Scott Air Force Base! 

=)My current profession is in HVAC, (heating, ventilation, and air conditioning), along with a decent knowledge of electrical and plumbing.  

The key is ensuring you run them like a business and have a way for tenants to request service in their units and also ensure they have clarity on what things they are responsible for (e.g. air conditioner filters, light bulbs, etc.).