There is no reason to hold.If you want to hold you must calculate the estimated cash flow based on a hypothetical 100% financing to determine if the cash flow is generated by the property, your equity/cash or a combination of both income streams. 

@Karen Rittenhouse thanks, for those details.

Please let me know if I'm not including any expenses or missing something key.Property Details:- 3 / 2, 1374 sqft, $89k askingExpenses ($802)P&I: $369Tax: $188Insurance: $70Utilities: $50Vacancy: 5% ($62.50)CapEx: 5% ($62.50)Total Investment (Down Payment + Closing + Repair) = $25,499Rent = $1250Cash Flow = $448Cash On Cash ROI = 21.08%This is a single family home in an area where I've competitively estimated the rent (Most units running between $1150 and $1450). 

The biggest variable I see people screw up is estimating the OE.

Part of my questioning now is to try and estimate tax liability for 2018.

If you are mathematical and want to get real detailed with it, learn how to write a discounted cashflow model in excel. 

For example, on the after repair value section of the calculator and the estimated repair costs, how do I find out what the typical costs are for a particular market (I know they vary from place to place from what I've been reading)?

https://www.roofstock.com/investment-property-details/kansascity-missouri/14920-fuller-ave-grandview-64030/1697409 There are a few things I have concern about turnkey properties: 1.

We estimated the value of the home based on similar sales so that estimate minus what we paid is where this amount comes from. - When did you purchase the home?

I spoke to the Brother of the wife ("B"), and discussed the possible situations- Unfortunately after working on the property details and researching the title for the property, I found out that the title belongs to both of them.