Check with zoning to make sure its a legal 2 unit house .Besides that if you separate the electric , and get it for $135K  its sounds pretty good . 

I am starting to think about the proper legal framework on my rentals to protect my personal assets/credit (such as an LLC, S-corp, etc.).

(We do not give tax, legal, or investment advice; you, the account holder, make the investment and strategy decisions.) 

I want to split legal responsibility for Mowing and snow removal between my two duplex tenants in their lease's.I'm looking for the exact language I can add into my lease's for the future.

For those willing to learn the rules and design an effective strategy within those boundaries, however, they can be very, very powerful wealth building tools. 

Of course, I'm assuming you are ethically and legally wholesaling properties. 

Where did you get the amounts for Supplies, Legal, and Inspections?  

Owner finance is great but not if you lose full control and if you use his model there could be legal ramifications as well. 

However, and after exhaustive phone calls to the county SO, Clerk of Courts & auditors' offices, no one knows or will give that answer because it is "legal" advice.

Opportunity zones are designated areas of each state (which tend to be more developmental/low income areas) where the reinvestment occurs.