I have a family realtor that I use to look at turnkey properties that I'll pay market value for more times than not, but I don't want to burden their time making 100s of offers a year for me if only a percentage of those will ever bare any fruit.  

If you spend under the $16,000 they pay under the Actual Cash Value payment (i.e. no depreciation reimbursed) then you get to keep the remainder... so say you end up being able to get everything done for $14,000, then you get to keep the remaining $2,000 which is not technically a profit, just that you were able to do the repairs in a more cost-effective way than the standard market price.

There's a part of the fence on the side of the house that collapsed but that doesn't effect the homes livability.So, I'm terrified I'll get this under contract but won't find a renter/buyer that is willing to do the work to fix the house.

But is it as cost effective? 

Combine OK's 8% + vacancy in one of the hottest rental markets nationally in the last 30 years,  its notoriety for storm damage there's likely lower hanging fruit in other markets. 

For example, 4% mortgage interest rate for somebody in 28% tax bracket would be (0.04*(1-0.28)) 2.88% effective rate that would be your guaranteed return.

@Douglas KrofcheckIf you have four separate units and wanted to install a central vacuum in each, it is possible each would need to be plumbed separately {for fire code reasons} - either back to a common mechanical room or within each unit - requiring a separate canister/motor to be installed for each.While a central vacuum would be a nice perk, I doubt it would be cost effective - it would likely be cheaper to finish all the units with hard flooring (no carpets) and buy a $50 Bissell Power Force bagless vacuum for each unit.  

My effective return on my down payment ends up being about 18%.  

Investors who know how to turn a wrench and swing a hammer will make big money on distressed real estate because there will be no other way to cost effectively rehab it.

To alter a month to month rental agreement you need to give them a written notice, typically 30 days before it takes effect.