Agree with most of your points, BUT half life of Ficam D!! Depends on where it is, if its dusted in a hole then it could remain active for a long time, same as in cavity wall, Thats no real difference to storing it in its original continer as long as its dry. When I do bees, I contact the local bee keepers first, so that they can come out and then agree destruction only course of action, certainly will help if ever investigated. My local bee keepers association have my details and will now call me if they have a nest to destroy
I do find that bees can "be" quite difficult to kill with in