My question is what kind of subtle or minimal event would trigger the need to pull a permit in a typical rehab other than the obvious?

Orkin will have given you advice on how to minimize the infestation. 

:)However the point if for minimal costs.

If done by QCD, non arms length, minimal fees.

I am risk averse haha...I accept some risk, but pretty minimal.

in terms of fees, the expense ratios are minimal (0.5%?)

They didn't bite but agreed to split the days - so I'm down to 7.5 days vacancy.I have since put in minimal effort but you'd better be ready to jump when the insanity begins.

Often times they will cut you a great deal on inspecting another property for you because you lost money and didn't buy the first one.That can help minimize your total losses to a degree.I would definitely get the 30 year mortgage.

The property was previously rehabbed in 2010 just needs minimal repairs to bring it back to a sale condition.

I was a contractor and even had some homeowners that didn't want to pay the minimal fee for the permits and I turned down those jobs.