Later in life another home I had was also subject to room rentals because with so much travel my insurance carrier threatened to cancel my coverage due to prolonged absences. 

Basically, what you are doing here is prolonging your ability to get your brain to kick into full action mode because you are deferring the start date mentally, which manifests itself into your everyday actions (or inaction).

The thing we want to avoid more than anything is having a non-paying tenant living above us who requires us to go through a prolonged eviction process which is more trouble in DC than most places.

And to avoid prolonged back and forth with the tenant.I hear bed bugs can be really hard to get rid of.  

He prolonged my job only a few days but he was an interesting character, not very helpful AT ALL.That makers sense from a 203K contractor standpoint.

I'm worried about a prolonged vacancy.

While that is true the demand side of the equation has been incentivized by a post-crash prolonged period of cheap credit.

I do not touch any of my profits from my properties ( unless they get up to a steady amount, usually 10K for me) this way that money is there for a new roof, furnace, hot water heater, whatever may come up. i just purchased a place and the first thing i did was have the roof replaced, 15K later, i know i am good for at least 25 years, if a storm does not rip it off, but now i know that property better have at least 15K in reserves. take what will be your worst case repair and make sure you have enough, or close to enough, in reserves for that property. but as others have stated, constant inspection of properties and equipment will help you prolong any of that, have an HVAC co. check the systems or a plumber check and maintain the furnace either every year or every other year, check roof for missing shingles or exterior for rotted boards, keeping the water out will maintain the structure within, exterior maintenance is a must.

But how much has the prolonged vacancy cost you thus far, $4-6-8k?

A lot of people who have only bought 1 property and sold for a loss would rather move on with their lives than dealing with the headache and heartache of prolonged litigation.