Dead equity will decrease your potential income as opposed to increasing it.

VRs can also increase long term rent as "affordable housing" properties decrease. 

Depending on your situation and the condition of the roof, I would recommend either a temporary repair to solve your immediate need, or a complete re-roof.  

If you are looking for high level analysis you probably won't find it in a forum post, you might look on Upwork.com and see if you can find someone who specializes in the area of analysis you are interested in and is willing to take on a temporary side job for a fee.

I certainly understand your mindset, however I would go with the 2nd rental property rather than paying off the mortgage right away.You might initially have less cash flow, but rental income should increase while your mortgage payment should only be decreasing (assuming you don't have an adjustable rate mortgage).I also like the idea of having more than 1 rental property because, if each property is cash flowing like they should be, you have more of a financial cushion during periods in which one property is vacant.

If you just had a really busy month and then the work drops off, you're then looking at terminating someone's employment or at least decreasing their hours.

That is my big question on this whole deal, what has caused him not to make payments, and is it temporary or permanent???

It is part tech so the value could also increase or decrease with any new updates.

Frankly they are a good idea to decrease slipperiness too.

Would this effect the property value by decreasing the income I could have had for this unit or could rehab be considered a years rent for tax and property value purposes?