Great points, Jeff.
Wish I had a dollar for every time a citizen-runner who knows I measure said, "man, you need to do something about the 'XYZ' course." My response is that I do not chase down RD's; if they want me to measure I easy enough to find.
Most of the race directors in this area - save one or two - aren't concerned about distance certification. And I usually make no bones about the fact I will not run their races because of that fact. Most of the races here are put on by RRCA clubs and I represent the national organization - funny how several of the non-RRCA clubs/events have taken an interest in getting races measured, though.
Good calendar, too. I try to put the certificate information on my calendar postings if I know it.