The realtor's communication with this tenant does not seem to be helping. 2) If she actually moved in, it is 95% likely she may have additional tenant protections due to her age and medical condition.

Also in addition to vetting a deal sponsor, take an alternative route and ask that are currently equity partners in someone else's deals as to what their experiences have been so far.

I'm looking forward to building valuable relationships 

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

Why are they getting rid of it... that will help you tailor your offer to be more valuable. 

Being able to close in 30 days or even sooner is more valuable than saving a fraction of a point on the interest rate, in my opinion.  

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.

The nuggets of info you gain and so incredibly valuable.