I'd like to revisit SctDad's original request:
"Does anyone out there have suggestions for how to break down campsite duties. We are going on an overnight trip and I was wondering what would be the best way to get everyone involved with campsite responsibilities."
In all fairness, he didn't ask for a risk management assestment or a discertation on Guide to Safe Scouting.
Since it's a Cub activity it seems the answer to your question is to divide it up amongst the Dens/families. Arranging it ahead of time, like at a Pack meeting or a pack committee meeting, would help make the process go smoother. Troops use a duty roster within the patrols when they camp, and there's no reason that the idea cannot be adopted to a Cub family campout.
As for the "other stuff", it's paramount to ensure that the BSA rules are being followed. You are not personally responsible for every part of the plan or campout. A good leader makes sure that they have the resources available to meet the BSA rules and trusts the other people to do their part, whether it's to hold the appropriate training card/certificate, plan the outing to BSA guidelines, etc.