My reply to your original question would be, how much air is there?  

It needs a LOT of work/complete gut - central air would need to be installed, needs a new roof, all new windows, new flooring, new kitchen, new baths, extensive drywall repair, etc etc.

Also it would literally suck the warm air out of the house and we found issues with the chimney.

I am also serving in the Air Force Reserves 13 yrs AF now. (10 yrs prior service Army) looking to retire early in 2018.

@Mindy Jensen,good catch on the grading under the house.hope you rented/bought an extra pump just in case.now off-topic, this-old-house had a few episodes where they explained the types of sump-pumps.they had mentioned one pump that runs no electricity, using water pressure from city water.many houses in chicago area had basement floods because there was no power for extended periods of time, which eventually drain even the battery backup.

Reduce the output pressure to about 30-40 PSI and fire it up.  

-  Funny story - when we bought our current house, the realtor staged it herself, and had put air beds on top of cardboard boxes (to raise it) then made the bed to hide it all.  

One thing missing from here is any employee costs if you're going to have management or maintenance staff.OPERATING EXPENSES Repairs and MaintenanceApplianceRepairElectrical RepairCredit ReportsCleaning or JanitorialRoof RepairPaintingHVAC (Heat, Ventilation, Air)ApplianceReplacementLawn CareLockworkCarpet/Floor CoveringsPest ControlPlumbing RepairEviction/DispossessoryExpenseManagementElectricityWater & SewerOPERATING EXPENSEPaintingRoofingPlumbingGround MaintenanceLock & KeyDumpsterElectrical RepairHeat/CoolRepair& ReplacementTermite/Pest ControlCarpetCleaning/ReplacementEviction ExpenseApplianceRepair/ReplacementElectricityWater/SanitationMisc.

Air everything out best you can. 

If you live in a home that has a low pressure sewer system or condo on the bottom floor of a building with a bunch of units above, invest in a $100.00 sewer backflow check vlave to be placed on the main sewer line leaving your home or unit.