Your ROI is actually decreased!!!  

And if rates decrease low end properties like this may appreciate the fastest. 

You can however significantly decrease you monthly living payment if that’s the goal.

4-If in Q#1 the S/U increases by $15k, then our Cash on Cash Return ("CCR") would decrease proportionally due to having a larger denominator.

But I’ve noticed the trend decreasing fortunately.

I would decrease my cash flow (not accounting for maintenance yet) on the property A. 

While this rate adjusts there's customarily a floor built into the loans and it's unclear how quickly the fed rate will decrease.  

Even if you moved to a less expensive home in the same areas, with the current interest rates, you are unlikely to decrease your mortgage payments.

If your ARV is accurate though (and I like that you're being conservative) you would need a 10% market decrease to break even.

can you see where Columbus is heading...my primary doubled in value in 3-years...it will double again in the next 5...same story with my investment properties...you won't be able to buy a home in Columbus for under $600k in 15-years...every structure in this city is valued at 40-50% of value...coastal Cali is beautiful, but the combination of the environmental factors and natural disasters and decreasing rate of affordability mean you're about capped...so, you become a city of working class poor that sell their soul to the devil to afford rent in shared apartment and a bunch of affluent self-centered a$$holes in McMansions...sounds awesome.