They help bring me peace of mind that fixing up a property over time can be achievable and (hopefully) less stressful!

Takes the Stress off of doing R.E.

When cities and towns can't make ends meet, they have two choices (like any business): increase revenue or reduce expenses.In most cases the ability to reduce expenses is minimal at this point, and the far easier choice is to simply increase taxes.

Last stress test for short term, could you withstand no income on the property for 6 months? 

That could be you buying the home from the seller and the proceeds being used (at closing) to satisfy the debts or that could be negotiating a reduced payment to the debtors and "assuming" title in exchange for satisfying those debts.But . . . if you can't negotiate this with the seller, then the legal process of taking a home from someone is a foreclosure. 

What if cap rate goes up due to stress?   

You can modify the lease to make the tenant responsible, but compensate them with reduced rent. 

basically to find ways to reduce taxes and be more tax efficient.

However, she told me she found out she won’t be working full time again at her job until August 1 and has asked for a reduced rent starting in August of $100 less per month and no late fees.

I generally agree with this for people that want to continue growing their capital, and in many ways it is actually helping reduce your risk, since you will go from 2 to 8 units so a single vacancy doesn't effect the portfolio as much.The only caution I can add is make sure when calculating your cash flow, both on the existing properties taking into account your new debt service, and the new properties, that you truly are keeping enough in reserves.