Which equates to heirship issues, leins from the city for keeping the grass cut, interest in those leins depending on how old they are, and a host of other potential hiccups. 

If you could not pass these stress tests, then you should reevaluate your portfolio.And as @Steve Vaughan stated, risky loans such as balloons, ARM's, commercial, and owner financed loans, called loans, etc. really throws a big risky monkey wrench into the overall equations.  

But like any equation, you cant just blindly plug in numbers.   

Generally,Location+SF+Amenities+Market Demand = Rent (in dollars).Now think of the right side of that equation as a scale.

You're by the water, so a couple of specimen-sized palms somewhere would definitely be in order.All this should be easily done within your budget, and will DRAMATICALLY change the outward appearance/curb appeal and VALUE of the property, no question.Esthetics for a property don't have an exact mathmatical equation for ROI.

My employer does an employer match and since I have a good paying W2 the matched portion that comes out of my employer pocket equates to monthly cash flow of almost 4 properties that I don't have to purchase if I'm using my minimum number for a property at $200 a door cash flow, and this free money doesn't include any appreciation/interest growth just what the employer adds to my account until I retire.  

Or are kids in the equation?

You get more cash flow but it doesn't equate to higher returns.

Just need to adjust the way you perceive the market.For example, a $10,000 increase in NOI equates to a ~$140,000 increase in value in a 7% cap rate market but a $200,000 increase in a 5% cap rate market.

Conventional cash-out refi isn't in the equation.