(they aren't really mountains but big hills, very pretty) or live in the Mississippi delta in the southeast.

One of the largest employers in the state is Delta Airlines - they most likely will have trouble for months if not years.

It sounds like they have both have been delt a sour hand and took longer to start growing up. 

Grow the delta between what you earn and what you spend.  

Any rule of thumb for what I should ask for percentage wise when I'm bringing two sides of the deal delta to the table (Hustle, Knowledge) and my partner is bringing 100% of the financing.I want this to be a win for both of us.Thanks for the Help!

But most appraisals in my area are based on cap and income approach, not comps.Here in Vermont, and I’m in a college town, buyers that I know buy on cash flow because it shows wealth generation (the delta between income and expenses).  

If it is, is the delta between the increase rent versus the cost and vacancy of the rental worth it rather than just raising rent on the existing tenants?

I would be at a 5% delta to make 20% and more than likely be able to drop the 7% to like you said 4-5% with keeping the initial investment small.

The delta is $500 a month or 6K a year.

I believe that Delta's stock is the best run of the big legacy domestic carriers.