Still, if you’ve got someone on the ground who truly knows how to navigate these waters, it’s like being handed a map with all the back roads highlighted.

If you have a 6 bedroom in an area that does not have a university (students looking for shared space) or is in a family friendly place it may sit vacant longer between tenants.For Capex, try not to use a generic number - look at the roof, furnace, hot water tank, kitchen - when will each need to be done and what will it cost?

In addition, I will also be paying much closer attention to water flow patterns and signs of erosion around our next investment!  

Its extremely important when running tighter margins like what you're talking about to focus on age of HVAC, water heater, appliances, roof, etc.

The rental might be vacant for a month,(8% loss) or a tenant might not pay for a month while you pay to evict them.(8-16% loss)  A $1,000 appliance/water heater, or a $8k rook or hvac unit might go out.(5-40% loss)  You should be paying a PM 8%.

Given this is where my major operating expenses fell (beyond taxes and insurance), keeping this cost lower, by average, helps my cash flow.I invest in older neighborhoods, so the 2-4 unit properties, typically have single water meter, maybe single electric, and many have radiator heat with a single boiler.  

Ok, so maybe I am not getting it but I have a hot water boiler with separate zones for each unit.

An alternative to batteries is a "water battery". 

That certificate would show open taxes, water, housing violations, citations, condemnations, receiverships, construction liens and other municipal liens.

You might need a 2nd well if you're not on city water.