Great job on the flip too, small touches like the tile Wainscoting in the bath make a HUGE impact on potential buyers!

He has had a major impact on how I approach real estate.

Although water / environmental risks could be problematic. 

Just off the top of my head:Physical ThingsProperty inspection  (should have professionally inspected)All major systemsElectricalPlumbingHeatingRoofStructuralEnvironmentalEtc.Property conditionTenant ConditionProperty LocationNear noise / environmental factFinancial / PaperworkLeasesDurationRent AmountLate FeesCondition reportsTenant applicationsBasic Contact infoEmployment infoEmergency contact infoEmailTenant Estoppel StatementInsuranceProperty Tax statementWell, there is a quick start.  

The fact that the reason the contract has expired is because of the sellers doing has no impact here?

Ah, many factors at work here.If you would feel more comfortablly refinancing, your credit should obviously have an impact on your decision.

Great to have another construction guy around... and in particular, I believe your commercial background will serve you exponentially.The only thing positive about DC traffic is that it does keep me still enough (literally and figuratively) to soak up the podcasts... they make the insanity tolerable (so thanks @Joshua Dorkin and @Brandon Turner - the impact of your podcasts far exceeds the knowledge gained)!

Also explain how the % offered to the buyers agent will impact showing rates.

I would sure up that value of $40k to $48k that is a 20% swing and will a noticeable impact on the outcome.  

But of course if they are not admitting fault or willing to sign any paper, call the police right away.Best of all, take lots of pictures right away, showing the cars in the position immediately after the impact.