The people trying to put a significance to the spot have a point, to a degree. Halloween, cemetery, the cross....<quoted text> I'm in agreement about the place chosen for Karen. I don't think it had anything to do with the cemetery...I believe it was mere convenience. JMO :/
That blogger did say that this location was a premeditated plan. Just might be the only thing he was correct about.
When you do consider the different places Karen could have been placed, I don't see Bledsoe Cemetery as out of the ordinary. Being in the proximity of the house as it was, the entire family probably knew Harness road like the back of their hand. Could probably drive it blindfolded, or at least without headlights.
Like you, I see it as a matter of convenience.