Duck poop, worms, and compost.

I don't see why a duck poop compost would be unsafe. Composting that has heated would kill any pathogens, and if it is old and has been well drained it should not burn the plants. Pick a small area to test it on.

As long as the worms can move away from an area of compost that is hot, they will be fine. They will move to outer edges, or up or down. Keep lots of loose leaf litter on the top so they have shaded protection. I think you will find you end up with a much finer quality of compost if you add worms.

For a worm tower, do you mean the type that is a pipe embedded in the ground? I only see one down side to it...moles or opossums that will come after worms. A mole wrecked my garden last year and I have been trying to figure out a way to keep it out. Since they also eat termites, I do not actually want to kill it, but I do want a garden in which all my plants are not pushed out of the soil three times a day! The only plants that survived were the ones I had in earthbox style planters...grrrr....stupid mole!