If you have an active root...over time it will grow back in there unless you excavate, cut and remove. 

Typically 75% of rental income can be applied towards your DTI for qualification. 

So can I calculate my cash on cash return like below $40K(appreciation)/($42k(Down payment)+(2.1K(Monthly payment for Mortgage+HOA)*36)) = 40/(42+75.6)= 34% so the annual cash on cash return is about 1.34 to find the cubit root.

Can anyone recommend good companies to root cause  and implement solution to fix this issue?

I would say on a rental property that's unrealistic, if it really is an issue on a property, better to address the root cause.

I consulted with a real estate lawyer a few times this year who said it's very hard to sue for negligence and they advised against taking legal action, especially since the property manager at least followed through on the eviction and repairs.I've now asked the property management company to apply a $4k credit for all the challenges I've had working with them.

I guess I can't wrap my head around the fact that anyone can make an argument as to how the doors and windows being left open was not the root cause of this issue.

Hence, the decision was to make the flight using a single-engine plane.The same logic applies to multi-family properties: a fourplex has four times the vacancy risk of a single-family.

Generally no because the root system is still in place.

All of my family grew up near Baton Rouge and went to LSU, so I'm rooting for you.