The additional numbers and info you provided look good if it all goes to plan.

Create a mission statement and establish a management style that suits you.5.

It's 2 bed/1 bath each, and it's on a 10,000+ square foot lot with parking for 4 cars (two garage, two additional off-street). 

There's a lot of value add here, in addition to what's already there.  

Aggressively paying down the mortgage by supplementing the 500$ in cash flow with an additional $1,000 in personal income we would pay the mortgage of in approx. 10 years and save more than 120K in interest payments.

In regards to the Borrowers’ front-end ratio, does that figure not take into account the rent cash flow that would be coming from the additional units? 

I know a lien or unexpected issue could hinder selling the property quickly or add additional costs.

In addition to understanding ARVs I have implemented some fantastic software for my company that has all the built in metrics that allows me to create ARV reports in a snap.

My only non-lawyer additions from what I have read and doing DD on a park with LOs:No one really knows. 

I'd rather pay a PM and get an additional $560/Month net.